COMMUNICATION | doi:10.20944/preprints202009.0134.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Bacterial cellulose; Nisin; Antimicrobial activity; Stability
Online: 5 September 2020 (08:52:11 CEST)
Nisin is a 3.4 kDa antimicrobial peptide, produced by Lactococcus lactis (ATCC 11454). This bacteriocin can inhibit spores gemination and gram-positive bacteria development and has gained visibility in therapeutic use. The bacterial cellulose (CB) has been considered an ideal material and with high quality applied in food and medical-pharmaceutical inputs. Because of all this benefits, it is important to know the system proceeding of CB with nisin. Therefore, it was realize nisin release profile analysis of CBs was performed; analysis of the minimum inhibitory concentration (MIC) of nisin against Escherichia coli ATCC 25922, Pseudomonas aeuroginosa ATCC 9721 and Staphylococus aureus ATCC 10390; antimicrobial stability test, for 100 days at different temperatures of 4º, 25º and 37 ° C against microorganisms: S. aureus e L. sakei. The results show that nisin is released by the CB in 4 hours of contact with medium and the MIC of nisin is 78 µg/mL for S. aureus, doesn’t have gram-negative inhibition. It had stability until 100 days against L. sakei and 60 days for S. aureus. The system proved to be efficient and CB potentiated the antimicrobial action of nisin, acting as a selective barrier for other compounds present in the standard solution, serving as protection of the peptide at different temperatures. The CB loading system can be an ideal antimicrobial stability system for nisin.
ARTICLE | doi:10.20944/preprints202311.1751.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Biosorption; Bacterial Cellulose; Biosurfactant; Hormones; micropollutants; Drug
Online: 28 November 2023 (10:24:29 CET)
The contamination of aquatic environments by pharmaceutical products consistently takes the attention of researchers due to the compounds' toxicity even at low concentrations. In response, we have developed an ecologically sustainable biosurfactant derived from a microorganism and incorporated into the bacterial cellulose. This bioproduct, along with the bacterial cellulose itself, was employed as a sorbent for pharmaceuticals (hormones and paracetamol) present in water. Bacterial cellulose membranes were generated through the cultivation of Gluconacetobacter xylinus ATCC 53582. The biosurfactant was produced by pre-inoculating Bacillus subtilis in a synthetic medium, followed by immersing the bacterial cellulose membranes in the biosurfactant solution, for incorporation. Tests were conducted using water experimentally contaminated with parace-tamol and 17α-ethinylestradiol (EE2), evaluating the biosurfactant's effect on bacterial cellulose sorption. Paracetamol levels were analyzed using spectrophotometry, and EE2 levels were as-sessed using high-performance liquid chromatography. In summary, bacterial cellulose exhibited superior adsorption for EE2 compared to paracetamol. The incorporation of biosurfactant onto bacterial cellulose reduced hormone adsorption but enhanced paracetamol sorption. Our findings indicated that adsorption is more effective with bacterial cellulose in its original and freeze-dried forms, without the incorporation of biosurfactant. Notably, we achieved more promising results in remediating the hormone EE2 compared to the paracetamol.
ARTICLE | doi:10.20944/preprints202010.0573.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: implant; bacterial cellulose; patch; myocardial infarction; cell; delivery
Online: 28 October 2020 (08:59:09 CET)
Biologic scaffolds have become an attractive approach for repairing the infarcted myocardium and have been shown to facilitate constructive remodeling in injured tissues. This study aimed to investigate the possible utilization of bacterial cellulose membrane patch containing cocultured cells to limit the myocardium's post-infarction pathology. Myocardial infarction was induced by ligating the left anterior descending coronary artery in 45 Wistar rats, and patches with or without cells were attached to the hearts. After one week, the animals underwent echocardiography for assessing ejection fraction and left ventricular end-diastolic and end-systolic volumes. Following the patch formation, cocultured cells retained viability of >90% over 14 days in culture. The patch was applied to the myocardial surface of the infarcted area after staying 14 days in culture. Interestingly, the bacterial cellulose membrane without cellular treatment showed higher preservation of cardiac dimensions; however, we did not observe improvement in the left ventricular ejection fraction of this group compared to coculture treated membranes. Our results demonstrated an important role for bacterial cellulose in supporting cells known to produce cardioprotective soluble factors and may thus provide effective future therapeutic outcomes for patients suffering from ischemic heart disease.
REVIEW | doi:10.20944/preprints202307.0915.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: Iron oxides; Synthesis; SPIONs; magnetism; bacterial cellulose; new materials
Online: 13 July 2023 (10:52:50 CEST)
Iron oxide nanoparticles have been investigated due to their suitable characteristics for diverse applications in the fields of biomedicine, electronics, water/wastewater treatment and sensors. Maghemite, magnetite and hematite are the most widely studied iron oxide particles and have ferrimagnetic characteristics. When very small, however, these particles have superparamagnetic properties and are called superparamagnetic iron oxide nanoparticles (SPIONs). Several methods are used for the production of these particles, such as coprecipitation, thermal decomposition and microemulsion. However, the variables of the different types of synthesis must be assessed to achieve greater control over the particles produced. In some studies, it is possible to compare the influence of variations in the factors for production with each of these methods. Thus, researchers use different adaptations of synthesis based on each objective and type of application. With coprecipitation, it is possible to obtain smaller, more uniform particles with adjustments in temperature, pH and the types of reagents used in the process. With thermal decomposition, greater control is needed over time, temperature as well as the proportion of surfactants and organic and aqueous phases in order to produce smaller particles and a narrower size distribution. With the microemulsion process, the control of the confinement of the micelles formed during synthesis through the proportions of surfactant and oil makes the final particles smaller and less dispersed. These nanoparticles can be used as additives for the creation of new materials, such as magnetic bacterial cellulose, which has different innovative applications. Composites that have SPIONs, which are produced with greater rigour with regards to size and distribution, have superparamagnetic properties and can be used in medical applications, whereas materials containing larger particles have ferromagnetic applications. To arrive at a particular particle with specific characteristics, researchers must be attentive to both the mechanism selected and the production variables to ensure greater quality and control of the materials produced.
ARTICLE | doi:10.20944/preprints202108.0312.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Komagataeibacter rhaeticus; Bacterial cellulose; Crude glycerol; Minimal medium; Whole-genome analysis; Acetate
Online: 16 August 2021 (08:32:19 CEST)
Komagataeibacter spp. have been used for the bioconversion of industrial wastes and lignocellulosic hydrolysates to bacterial cellulose (BC). Recently studies have demonstrated the capacity of Komagataeibacter spp. in the biotransformation of inhibitors found in lignocellulosic hydrolysates, aromatic lignin-derived monomers (LDMs) and acetate. In general, detoxification and BC synthesis from lignocellulosic inhibitors requires a carbon flow from acetyl-coA towards tricarboxylic acid and gluconeogenesis, respectively. However, the related molecular aspects have not yet been identified in Komagataeibacter spp. In this study, we isolated a cellulose producing bacteria capable of synthesizing BC in a minimal medium containing crude glycerol, a by-product from biodiesel production process. The isolate, affiliated to Komagataeibacter genus, synthesized cellulose in minimal medium containing glucose (3.3±0.3 g/L), pure glycerol (2.2±0.1 g/L) and crude glycerol (2.1±0.1 g/L). Genome assembly and annotation identified four copies of bacterial cellulose synthase operon and genes for redirecting the carbon from central metabolic pathway to gluconeogenesis. According to the genome annotations, a BC production route from acetyl-CoA, a central metabolic intermediate, was hypothesized and was validated using acetate. We identified that when K. rhaeticus ENS9b was grown in minimal medium supplemented with acetate, BC production was not observed. However, in presence of readily utilizable substrate, such as spent yeast hydrolysate, acetate supplementation improved BC synthesis.
ARTICLE | doi:10.20944/preprints202101.0045.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Kombucha tea; microbial diversity; bacterial cellulose; Komagataeibacter xylinus; repetitive elements sequence-based rep-PCR; typing
Online: 4 January 2021 (13:24:41 CET)
Bacterial cellulose (BC) is receiving great attention due to its unique properties such as high purity, water retention capacity, high mechanical strength, and biocompatibility. However, the production of BC has been limited because of high cost and low productivity. In this light, the isolation of new BC producing bacteria and selection of high productive strains became a promising issue. Kombucha tea is a fermented beverage in which the bacteria fraction of the microbial community is composed mostly by strains belonging to the genus Komagataeibacter. In this study Kombucha tea production trials were performed starting from a previous batch, and bacterial isolation was conducted along cultivation time. From the whole microbial pool, 46 isolates were tested for their ability in producing BC. The obtained BC yield ranged from 0.59 g/L, for the isolate K2G36, to 23 g/L for K2G30 used as the reference strain. The genetic intraspecific diversity of the 46 isolates was investigated using two repetitive-sequence-based PCR typing methods, which are the enterobacterial repetitive intergenic consensus (ERIC) elements and the (GTG)5 sequences, respectively. The results obtained using two different approaches revealed the suitability of the fingerprints techniques, showing a discrimination power, calculated as D index, of 0.94 for (GTG)5 rep-PCR and 0.95 for ERIC rep-PCR. In order to improve the sensitivity of the applied method, a combined model from the two genotyping experiments was performed, allowing to discriminate among strains.
ARTICLE | doi:10.20944/preprints202105.0608.v3
Subject: Chemistry And Materials Science, Biomaterials Keywords: nanocomposites; bacterial cellulose; ceria nanoparticles; thermal properties; swelling; mechanical behavior; biomedical applications; stem cells proliferation; gene expression
Online: 17 June 2021 (10:02:24 CEST)
A technique for fabrication of bacterial cellulose-based films with CeO2 nanofiller has been developed. The structural and morphological characteristics of the materials have been studied, their thermal and mechanical properties in dry and swollen states having been determined. The preparation methodology makes it possible to obtain composites with a uniform distribution of nanoparticles. The catalytic effect of ceria regarding the thermal oxidative destruction of cellulose has been confirmed by TGA and DTA methods. An increase in CeO2 content led to an increase in the elastic modulus (a 1.27-fold increase caused by the introduction of 5 wt.% of the nanofiller into the polymer) and strength of the films. This effect is explained by the formation of additional links between polymer macro-chains via the nanoparticles’ surface. The materials fabricated were characterised by a limited ability to swell in water. Swelling caused a 20- to 30-fold reduction in the stiffness of the material, the mechanical properties of the films in a swollen state remaining germane to their practical use. The application of the composite films in cell engineering as substrates for the stem cells’ proliferation has been studied. The increase in CeO2 content in the films enhanced the proliferative activity of embryonic mouse stem cells. The cells cultured on the scaffold containing 5 wt.% of ceria demonstrated increased cell survival and migration activity. An analysis of gene expression confirmed improved cultivation conditions on CeO2-containing scaffolds.
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Rhodococcus equi; Rhodococcus hoagii; bacterial nomenclature; bacterial taxonomy; bacterial systematics
Online: 2 February 2020 (06:56:32 CET)
A recent taxonomic study confirmed the synonymy of Rhodococcus equi (Magnusson 1923) Goodfellow and Alderson 1977 and Corynebacterium hoagii (Morse 1912) Eberson 1918. As a result, both R. equi and C. hoagii were reclassified to Rhodococcus hoagii comb. nov. in application of the principle of priority of the Prokaryotic Code. Being R. equi a well-known animal and zoonotic human pathogen, and the name solidly established in the veterinary and medical literature, we and others argued that the nomenclatural change may cause error and confusion and be potentially perilous. We have now additionally found that the nomenclatural type of the basonym C. hoagii, ATCC 7005T, does not correspond with the original description of C. hoagii in the early literature. Its inclusion as the C. hoagii type on the Approved Lists 1980 results in a change in the characters of the taxon and in C. hoagii clearly designating two different bacteria. Moreover, ATCC 7005, the only strain in circulation under the name C. hoagii, does not have a well documented history; it is unclear why it was deposited as C. hoagii and a possible mixup with a Corynebacterium (Rhodococcus) equi isolate is a reasonable assumption. We therefore request the rejection of Rhodococcus hoagii as a nomen ambiguum, nomen dubium and nomen perplexum in addition to nomen periculosum, and conservation of the name Rhodococcus equi, according to Rules 56ab of the Code.
ARTICLE | doi:10.20944/preprints202309.0622.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: yaks; cattle; blood metabolism; rumen bacterial; fecal bacterial
Online: 11 September 2023 (09:20:22 CEST)
This study compared growth performance, serum biochemical indicators, rumen fermentation parameters, rumen bacterial structure, and fecal bacterial structure of cattle and yaks, fed for two months, given a feed containing concentrate to roughage ratio of 7: 3 on dry matter basis. Compared with cattle, yak showed better growth performance. The serum biochemical results showed that the albumin: globulin ratio in yaks serum was significantly higher than that in cattle. Aspartate aminotransferase, indirect bilirubin, creatine kinase, lactate dehydrogenase and total cholesterol were significantly lower in yaks than that in cattle. Rumen pH, acetate to propionate ratio, and acetate were lower in yaks than in cattle while the lactate in yaks was higher than in cattle. There were significant differences in the structure of ruminal as well as fecal bacteria between cattle and yaks. The prediction of rumen bacterial function showed that there was metabolic difference between cattle and yaks. In general, the metabolic pathway of cattle was mainly riched in de novo synthesis of nucleotides, while that of yaks was mainly riched in the metabolic utilization of nutrients. This study provides a basis for understanding the rumen ecology under the condition of high concentrate diet.
CASE REPORT | doi:10.20944/preprints201912.0170.v1
Subject: Medicine And Pharmacology, Dermatology Keywords: sphingomonas; gram-negative bacterial infection; skin disease; bacterial
Online: 12 December 2019 (10:01:35 CET)
Sphingomonas paucimobilis is an opportunist pathogen bacillus gram-negative aerobic with a rare occurrence. We present a case in an immunocompetent man successfully treated by surgical debridement, purulent drainage and with an associated course of antibiotics. A large necrotic infection, approximately 5 cm x 3 cm, in a 74-year-old man was identified. Empirical antibiotic therapy with ciprofloxacin 400mg EV 12/12 hours, associated with clindamycin 600mg EV 6/6 hours and pain control was done through dipyrone 1gr, tramadol 400 mg. Deep venous thrombosis was prevented through the prescription of enoxaparin 40mg subcutaneous once a day during hospitalization. The case was well illustrated with pictures throughout treatment. Complete healing was achieved after 90 days. Herein, we present a case of cutaneous contamination. The presented case is the third cutaneous contamination case reported in the literature and the first reported case in the Amazonia region in Brazil.
CONCEPT PAPER | doi:10.20944/preprints202107.0546.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Bacterial nomenclature; taxonomy; microbial genomics
Online: 23 July 2021 (14:22:59 CEST)
The remarkable success of taxonomic discovery, powered by culturomics, genomics and metagenomics, creates a pressing need for new bacterial names, while holding a mirror up to the slow pace of change in bacterial nomenclature. Here, I take a fresh look at bacterial nomenclature, exploring how we might create a system fit for the age of genomics, playing to the strengths of current practice, while minimising difficulties. Adoption of linguistic pragmatism, obeying the rules while treating recommendations as merely optional will make it easier to create names derived from descriptions, from people or places or even arbitrarily. Simpler protologues and a relaxed approach to recommendations will also remove much of the need for expert linguistic quality control. Automated computer-based approaches will allow names to be created en masse before they are needed, while also relieving microbiologists of the need for competence in Latin. The result will be a system that is accessible, inclusive and digital, while also fully capable of naming the unnamed millions of bacteria.
REVIEW | doi:10.20944/preprints202103.0358.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Nanoparticle; Bacterial; Biotechnology; Biomedical; Application
Online: 13 March 2021 (00:17:05 CET)
On estimation scales ranging from 0.1 nm to 100 nm, the nanoscale is part of the capacitance components of the physical-synthetic and natural environment. Dimensionality, morphology, structure, uniformity, and agglomeration are all used to classify nanoparticles. Its functionality and effect on the environment and species are influenced by its shape and morphology. The priority research is to determine the effects of nanoparticles on any biological entity that is necessary when designing nanotechnology-based biotechnological and biomedical products. Bacteria have a remarkable ability to reduce metal ions, making them one of the most promising candidates for nanoparticle biosynthesis. Nanoparticles have been researched in the biomedical field for antimicrobial, biosensor, diagnostic imaging, and drug delivery applications. These natural technologies appear to be capable of producing stable nanoparticles with well-defined dimensions, morphologies, and compositions by optimizing reaction conditions and selecting the best bacteria. This work includes a list of the most commonly used microorganisms and associated Nanoparticles, as well as a discussion of current biotechnology and biomedical developments.
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: actin cytoskeleton; chlamydia; bacterial pathogenesis
Online: 9 December 2019 (03:53:26 CET)
The actin cytoskeleton is crucially important to maintenance of cellular structure, cell motility and endocytosis. Accordingly, bacterial pathogens often co-opt the actin-restructuring machinery of host cells to access or create a favorable environment for their own replication. The obligate intracellular organism Chlamydia trachomatis and related species exemplify this dynamic: by inducing actin polymerization at the site of pathogen-host attachment, Chlamydiae induce their own uptake by the typically non-phagocytic epithelium they infect. The interaction of chlamydial adhesins with host surface receptors has been implicated in this effect, as has the activity of the chlamydial effector TarP (translocated actin recruitment protein). Following invasion, C. trachomatis dynamically assembles and maintains an actin-rich cage around the pathogen’s membrane-bound replicative niche, the chlamydial inclusion. Through further induction of actin polymerization and modulation of the actin-crosslinking protein myosin II, C. trachomatis promotes egress from the host via extrusion of the inclusion. In this review, we present the experimental findings that inform our understanding of actin-dependent chlamydial pathogenesis, discuss lingering questions, and identify potential avenues of future study.
ARTICLE | doi:10.20944/preprints201810.0698.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: optic biosensor; fluorescence; bacterial detection
Online: 30 October 2018 (03:44:11 CET)
The importance of detecting bacteria in various food products is ever-increasing, due to recent food trends that lend themselves to food contamination. Additionally, the detection of probiotics in food products is of increasing importance to consumers, who realize the benefits of probiotics on one’s diet. Existing technologies for detection of bacteria in food are accurate, but most are slow, increasingly costly and unsuitable for applications outside of research laboratories. Optic approaches have recently emerged as an alternative, allowing rapid detection of bacterial presence. This study employs a portable kinetics fluorometer, fabricated in-house, in conjunction with NADH sensitive fluorescence reporter for analysis of various food products. The presence of bacteria is detected in 5 minutes. Both pathogenic and probiotic bacteria were detected in food products, such as raw chicken and beef, spoiled lettuce and contaminated water, yogurt, and kombucha tea. The cellular activity of two probiotic pills was also verified. All samples displayed varying levels of bacterial activity. The study indicates the viability of biosensors being used as an alternate method to detect bacteria in food products – and the viability of a fluorescence-based biosensor to detect viable bacteria. The approach is suitable for both laboratory and field determinations.
ARTICLE | doi:10.20944/preprints202308.0855.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Canaries; Serinus canaria; gut bacterial microbiota; bacterial communities; reproduction; reproductive cycle; 16S rRNA gene sequencing
Online: 10 August 2023 (11:14:53 CEST)
Investigation of bacterial communities is on the rise both in human and veterinary medicine. Their role in health maintenance and pathogenic mechanisms is in the limelight of infectious, metabolic, and cancer research. Among the most considered, gut bacterial communities takes the cake. Their part in animals was assessed mainly to improve animal production, public health, and pet management. In this regard, canaries deserve attention, being a popular pet and source of economic income for bird-keepers, for whom breeding represents a pivotal point. Thus, the aim of the present work was to follow gut bacterial communities’ evolution along on whole reproductive cycle of 12 healthy female canaries. Feces were collected during parental care, molting, and resting phase, and submitted for 16S rRNA sequencing. Data analysis a substantial presence of Lactobacillus aviarius along all the phases, and a relevant shift of microbiota during molting and rest due to an abrupt decrease of Vermiphilaceae family. Although the meaning of such change is not clear, future research may highlight unforeseen scenarios. Moreover, Lactobacillus aviarius may be deemed for normal bacteria flora restoration in debilitated birds, perhaps improving their health and productivity.
REVIEW | doi:10.20944/preprints202306.1921.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Antibiotic resistance; Drug designing; Bacterial mutation; Bacterial evolution; Horizontal gene transfer; Public and agricultural health
Online: 27 June 2023 (13:55:21 CEST)
Antibiotic resistance has emerged as one of the major concerns to public human health due to issues in treatment and control of major infectious diseases. From discovery of penicillin in 1940, the antibiotic resistance originated and now developed the microorganisms as resistive strains to the major available antibiotics. Furthermore, studies on this captivating activity of the microbes provide insight into the complexities of microbial physiology and may offer some guidance in preventing the onset and consequent development of antibiotic resistance. Despite of initiatives taken in last few decades to overcome the issues, the trends of antibiotic resistance gained much peak. Antibiotic resistance appears to have emerged as a result of various factors including antibiotics being misused and overused in both the medical field and the agricultural sector. Important factors in the development of antibiotic resistance also include bacterial mutation, unplanned evolution, and horizontal gene transfers. In addition, antibiotics resistance imposed the financial consequences to public health and drug development research. Future advancements related to innovative antibiotics and molecular drug designing become challenge for researchers due to intensive multiple antibiotics resistance among human population. Many researches have been conducted on origin, evolutionary aspect of antibiotic resistance and mechanisms of antibiotics resistance, but its effect on future drug development is little understood. Therefore, the recent review will highlight the role of antibiotic resistance in drug designing and impacts of antibiotic resistance on drug development in future.
ARTICLE | doi:10.20944/preprints202310.0945.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: pigeon pea; bacterial diversity; metataxonomic analysis
Online: 16 October 2023 (13:15:21 CEST)
: With the increase in demand for non-dairy starter cultures and probiotic bacteria as carriers, the use of legumes (also called pulses) as an alternative has gained momentum. In this study, we investigated the diversity of bacterial communities in samples of pigeon pea (Cajanus cajan L. Millsp.) soaked in water for 12 h and 24 h. We soaked 500 g of pigeon pea in sterile distilled water at room temperature (± 25 °C) for 12 h and 24 h; 10 mL of the soaking water was then collected to measure the bacterial diversity using a metataxonomic analysis. The V1–V9 regions on the 16S ribosomal RNA gene were amplified using 27F and 1492R primers under specific polymerase chain reaction conditions for the bacterial identification. Genomic DNA (130 ng) was sequenced on a R9.4 flow cell by Oxford Nanopore Technologies using a GridION sequencer. Library preparations were initiated using a Native Barcoding Kit 24 V14 (SQK-NBD114.24). Primary data were acquired using MinKNOW version 22.05.7. A total of 13 bacterial families and 89 genera were identified in the pigeon pea sample soaked for 12 h; 26 families and 90 genera were identified in the pigeon pea sample soaked for 24 h. Among the bacterial families identified, the five predominant families in both samples were Enterobacteriaceae, Erwiniaceae, Yersiniaceae, Pectobacteriaceae, and Lactobacillaceae. According to the relative abundance of the identified bacterial genera, the following nine genera were predominant in both samples: Enterobacter, Klebsiella, Citrobacter, Pantoea, Kosakonia, Pseudoenterobacter, Pluralibacter, Leclercia, and Kluyvera. At a genus level, a slight increase in the abundance of Klebsiella, Kosakonia, and Pluralibacter and a slight decrease in the abundance of Citrobacter were observed after prolonged incubation from 12 h to 24 h. The values of five diversity indices revealed that the sample soaked in water for 24 h had a richer bacterial abundance and diversity than the 12 h sample. Shannon and Simpson values revealed a higher bacterial diversity in the sample collected at 24 h than the sample collected at 12 h. Species observations and abundance-based coverage estimator (ACE) values demonstrated that the sample collected at 24 h harbored a higher bacterial richness than the sample collected at 12 h. These findings indicated that the bacterial diversity in the pigeon pea samples increased with the soaking time. The bacterial communities during the soaking of the pigeon pea samples were dominated by the Enterobacteriaceae family and Enterobacter genus. The presence of bacterial genera such as Lacticaseibacillus, Lentilactobacillus, and Secundilactobacillus was notable because of their importance as starter cultures for fermented plant-based milk products, including pigeon pea beverages for lactose-intolerant individuals or individuals with malnutrition.
ARTICLE | doi:10.20944/preprints202308.1582.v2
Subject: Biology And Life Sciences, Plant Sciences Keywords: legumes; siderophores; IAA; biomass; bacterial richness
Online: 26 September 2023 (02:24:00 CEST)
Calicotome villosa is a eurioic legume with broad distribution in the south of Europe. It can grow in almost any type of soils as well as in humid and dry and nutrient deficient ecosystems. The broad distribution and eurioic nature of C. villosa may be attributed to its ability to establish symbiotic associations with plant growth promoting (PGP) bacteria housed in the nodules and rootless. This study examined legume-microbe symbiosis of C. villosa growing in two contrasted locations, hill top with high sun irradiance and drought; and a valley bottom, with low level or radiation and sufficient soil humidity for plant growth. Calicotome villosa adult plants established symbiotic in-teractions with bacteria in six genera, Pseudomonas, Stenotrophomonas, Bacillus, Paenibacillus, Brevicacterium and Rhizobium as well as one uncultured bacteria. Plants growing in the hill top had associated lower bacterial richness than those grown at the valley bottom. All strains were drought tolerant and produced siderophores, IAA, HCN and NH3 that stimulated plant performance in both, C. villosa plants and other four legumes commonly present in the understory of the shrubs communities The legumes’ capacity to selectively host symbiotic bacteria that enhance plant survival in harsh conditions partly accounts for the diverse partnerships between C. villosa plants and their symbionts, ultimately explaining the wide distribution of this plant species.
ARTICLE | doi:10.20944/preprints202303.0218.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Analysis; bacterial; pathogens,bacteriology; human health
Online: 13 March 2023 (06:23:55 CET)
The study was geared toward isolating, characterizing and identifying bacterial pathogen in sachet water in addition to determines the bacterial count of the sachet water sold in Obi Local Government Area. Twelve sachet water samples from different companies were analyzed using standard microbiological methods. The microorganism found are Escherichia Coli, Staphylococcus aures, Salmonella spp, with Staphlococuss aureus showing the highest incidence (50%), observed by Escherichia coli (29.17%) and Salmonella spp with the lowest occurrence (20.8%). The presence of these microbes in drinking water possesses a threat to life. The findings consequently suggest that some of the sachet water sold in obi L.G. A are not healthy for human intake and are risky to health. Hence there's need for strict concern and routine monitoring by regulatory agencies to make sure that appropriate treatment is applied inside the manufacturing of exceptional and safe sachet drinking water. This study is aimed to analyze the bacteriological quality of some selected sachet water in Obi Local Government Area of Benue State, Nigeria.
ARTICLE | doi:10.20944/preprints202209.0131.v1
Subject: Medicine And Pharmacology, Obstetrics And Gynaecology Keywords: bacterial vaginosis; recurrent vaginitis; biofilm; polycarbophil
Online: 9 September 2022 (07:33:38 CEST)
Recurrent bacterial vaginosis (RBV) after antibiotic treatments has a relapse rate of 35% within 3 months and 60% within 12 months. Products containing polycarbophil (PLGG), that inhibits bacterial growth and mucoadhesive property, can impair biofilm formation. Here are shown the results of the POLARIS (Polybactum® to assess Recurrent Bacterial Vaginosis) study. The first phase was an interventional, open-label, non-controlled, and multicentre trial enrolling 56 women in Italy and Romania. The second phase was an observational 10-month follow-up without treatment conducted only in Romania. After 3 cycles with PLGG, only 8 BV recurrences out of 54 evaluable patients were identified (rate 14.81%) and for 26 out of 39 patients (66.67%) was evidenced positive effect on Lactobacilli in the vaginal secretions. In the follow-up 35 patients were observed after PLGG stopping treatment; 1 RBV (2.86%) at the 4th month and an additional 6 cases (17.14%) were evidenced at the end of the follow-up period. Therefore, no recurrence was evidenced in 12 subjects (34.28%) at 10th ± 2 months after the end of the PLGGtreatment. The use of PLGG vaginal ovules in the treatment of BV reduces the rate of relapses and improves the microbiological parameters (positive effect on Lactobacilli in 66.7 % of cases).
REVIEW | doi:10.20944/preprints202204.0309.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: bacteriophages; biocontrol; food production; bacterial resistance
Online: 29 April 2022 (15:49:21 CEST)
Bacteriophages have been recognized as potential biocontrol agents in the food industry. Bacteriophages have been proposed for a variety of applications within this industry including bio preservation, pathogen detection, and as an alternative treatment method to antibiotics in animal health. The potential applications of bacteriophages are widespread throughout the entire food production process and serve to enhance food quality, prevent foodborne illnesses, and enhance the efficiency of production. The ability of bacteriophages to lyse bacterial targets with high specificity and pose no threat to mammalian cells or natural microbiota is unique and relevant in terms of suitability for food safety. This review will outline potential and current applications of bacteriophages and their respective impacts on the field.
ARTICLE | doi:10.20944/preprints202111.0031.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: aquaponics; metabarcoding; bacterial communities; carbohydrases; phytases
Online: 2 November 2021 (10:12:35 CET)
Aquaponics are efficient systems that associate aquatic organisms’ production and plants by recirculating water and nutrients between aquaculture and hydroponic tanks. In this study, we have characterised the bacterial communities in the fresh water aquaponics system that can mineralise polysaccharides and phytate by producing carbohydrate degrading enzymes and phytases, by 16S rRNA gene sequencing and in vitro culture techniques. Around 20% of the operational taxonomic units (OTUs) identified were previously reported to carry fibre-degrading enzymes putative genes, namely β-glucanase (1%), xylanase (5%) or cellulases (17%). Ten % of the OTUs were previously reported to carry putative genes of phytases with different catalytic mechanisms, namely β-propeller (6%), histidine acid phytases (3%) and protein tyrosine phytase (<1%). Thirty-eight morphologically different bacteria were isolated from biofilms accumulated in fish and plant compartments, and identified to belong to the Bacilli class. Among these, seven could produce xylanase, 8 produced β-glucanase, 14 produced cellulase, and 11 isolates could secrete amylases. In addition, Staphylococcus sp. and Rossellomorea sp. could produce consistent extracellular phytate-degrading activity. The PCR amplification of β-propeller genes both in environmental samples and in the isolates obtained showed that this is the most ecologically relevant phytase type in the aquaponics systems used. In summary, the aquaponics system is abundant with bacteria carrying enzymes responsible for plant-nutrient mineralisation.
ARTICLE | doi:10.20944/preprints202106.0639.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Microscopy; Bacterial cell biology; Nanofabrication; Microfluidics
Online: 28 June 2021 (10:38:11 CEST)
Light microscopy is indispensable for analysis of bacterial spatial organization. However, imaging in bacteria is difficult due to their small sizes and the fact that most species are non-spherical, meaning they typically lie horizontally on a microscope coverslip. This is especially problematic when considering that many essential bacterial processes—such as cell division—occur along the short axes of these cells, and so are viewed side-on by standard microscopy. We recently developed a pair of methods to overcome this problem by forcing cells to stand vertically during imaging, named VerCINI (Vertical Cell Imaging by Nanostructured Immobilisation) and µVerCINI (Microfluidic VerCINI). The concept behind both methods is that cells are imaged while confined vertically inside cell traps made from a nanofabricated mould. By doing so, the short axes of the cells are rotated parallel to the microscope imaging plane and are imaged with high resolution. μVerCINI combines the vertical cell confinement with microfluidics so that vertical imaging can be done during fluid exchange, such as during antibiotic perturbations. Here, we provide a practical guide to implementing both VerCINI and µVerCINI, with detailed protocols and experience-based tips so that interested researchers can easily use one or both imaging methods to complement their current approaches.
REVIEW | doi:10.20944/preprints202009.0405.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: horizontal gene transfer; bacterial conjugation; phenotypic conversion; drug-resistance dissemination; bacterial biofilms; mobile plasmids; F plasmid
Online: 17 September 2020 (12:00:29 CEST)
Bacterial conjugation, also referred to as bacterial sex, is a major horizontal gene transfer mechanism where the DNA is transferred from a donor to a recipient bacterium by direct contact. Conjugation is universally conserved among bacteria and occurs in a wide range of environments (soil, plant surfaces, water, sewage, biofilms and host-associated bacterial communities). Within these habitats, conjugation drives the rapid evolution and adaptation of bacterial strains by mediating the propagation of various metabolic properties, including symbiotic life-style, virulence, biofilm formation, or resistance to heavy metals and, most importantly, resistance to antibiotics. These properties make of conjugation a fundamentally important process at the center of extensive study. Here, we review the key steps of conjugation by following the life-cycle of the F plasmid during transfer from the donor to the recipient cell. We also discuss our current knowledge of the extent and impact of conjugation within an environmentally and clinically relevant bacterial habitat, bacterial biofilms.
ARTICLE | doi:10.20944/preprints202308.1150.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: bacterial biofilm; Bacillus subtilis; Lactuca sativa; PGPR
Online: 16 August 2023 (08:13:31 CEST)
In Argentina there are urban areas of intensive cultivation around most of the big cities, where the soils may be unsuitable for some of the horticultural species and the use of chemical fertilizers is common. Bioinoculants based on plant growth promoting rhizobacteria (PGPR) could be an al-ternative for crop improvement, without affecting the environment. These formulations are gen-erally liquid, and their main disadvantage is the low viability of microorganisms. The objectives of this work were to evaluate a different inoculation method, the application of the biofilm pro-duced by Bacillus subtilis as a growth promoter on seeds of three varieties of Lactuca sativa. Biofilm was obtained under static culture conditions, the liquid (planktonic) inoculum was produced at 150 rpm. The major effects were observed with Bacillus subtilis subsp. spizizenii, that showed an-tifungal activity against phytopathogens, synthesize plant growth regulators (IAA, cytokinin and ABA) and solubilize phosphates. The best results were obtained with the Grand Rapid variety inoculated with biofilm, its positive effect was throughout the plant development until the har-vest time, when the bacterium was recovered from the interior of the roots. The biofilm of B. sub-tilis subsp. spizizenii would be an innovative and promising seed inoculant for horticultural spe-cies.
REVIEW | doi:10.20944/preprints202203.0042.v1
Subject: Medicine And Pharmacology, Obstetrics And Gynaecology Keywords: antimicrobial resistance; bacterial vaginosis; refractory; recurrent; treatment
Online: 2 March 2022 (10:11:03 CET)
Bacterial vaginosis (BV), the most common cause of vaginal discharge, is characterized by a shift in the vaginal microbiota from lactobacillus dominance to a diverse array of facultative and strict anaerobic bacteria which form a multi-species biofilm on vaginal epithelial cells. The rate of recurrence after therapy is high, often >60%. While the BV biofilm itself likely contributes to recurrent and/or refractory disease after treatment by reducing antimicrobial penetration, antimicrobial resistance in BV-associated bacteria including those, both within the biofilm and the vaginal canal, may be the result of independent, unrelated bacterial properties which are discussed in this paper. Our current recommendations for the treatment of refractory and recurrent BV are also provided.
ARTICLE | doi:10.20944/preprints202110.0140.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: performance; biodegradation; bacterial consortium; marine sponge; PAHs
Online: 8 October 2021 (12:09:30 CEST)
Every petroleum processing industry produces sewage sludge containing several types of poly-cyclic aromatic hydrocarbon (PAHs) components. The degradation of PAH components by physical, biological and chemical methods is not efficient. The use of marine sponge symbiont bacteria is considered an alternative method in the degradation and reduction of PAHs com-pared to the previous method. This study aims to explore the potential and performance of a consortium of sponge symbiont bacteria in degrading anthracene and pyrene. There are three types of bacteria (Bacillus pumilus strain GLB197, Pseudomonas stutzeri strain SLG510A3-8, Acineto-bacter calcoaceticus strain SLCDA 976) were mixed to form a consortium. The interaction between the bacterial consortium suspension and PAH components was measured at 5-day intervals for 25 days. The biodegradation performance of bacteria on PAHs samples was determined based on five biodegradation parameters. The analysis results showed a decrease in the concentration of anthracene (21.89%) and pyrene (7.71%), equivalent to a ratio of 3: 1. The data was followed by a decrease in the abundance of anthracene (60.30%) and pyrene (27.52%), an equivalent ratio of 2: 1. The level of degradation of the pyrene component is lower than that of the anthracene compo-nent, presumably due to the higher toxicity of pyrene and the more stable molecular structure, making it difficult for bacterial cells to destroy it. The biodegradation products are organic compounds of alcohol, aldehyde, carboxylic acids and a small proportion of aromatic hydrocarbon components. Keywords: performance; biodegradation; bacterial consortium; marine sponge; PAHs
REVIEW | doi:10.20944/preprints202103.0595.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: germination, bacterial cell wall, sporulation, germination, morphology
Online: 24 March 2021 (14:56:55 CET)
A fundamental question in biology is how cell shapes are genetically encoded and enzymatically generated. Prevalent shapes among walled bacteria include spheres and rods. These shapes are chiefly determined by the peptidoglycan (PG) cell wall. Bacterial division results in two daughter cells, whose shapes are predetermined by the mother. This makes it difficult to explore the origin of cell shapes in healthy bacteria. In this review, we argue that the Gram-negative bacterium Myxococcus xanthus is an ideal model for understanding PG assembly and bacterial morphogenesis because it forms rods and spheres at different life stages. Rod-shaped vegetative cells of M. xanthus can thoroughly degrade their PG and form spherical spores. As these spores germinate, cells rebuild their PG and reestablish rod shape without preexisting templates. Such a unique sphere-to-rod transition provides a rare opportunity to visualize de novo PG assembly and rod-like morphogenesis in a well-established model organism.
ARTICLE | doi:10.20944/preprints202310.0278.v1
Subject: Engineering, Chemical Engineering Keywords: Nitric oxide, Bacterial signaling, Quorum quenching, Biofilm, Biofouling
Online: 6 October 2023 (11:17:30 CEST)
Membrane biofouling is an inevitable challenge in membrane-based water treatment systems such as membrane bioreactors. Recent studies have shown that biological approaches based on bacterial signaling can effectively control biofilm formation. Quorum quenching (QQ) is known to inhibit biofilm growth by disrupting quorum sensing (QS) signaling, while nitric oxide (NO) signaling helps to disperse biofilms. In this study, batch biofilm experiments were conducted to investigate the impact of simultaneously applying NO signaling and QQ for biofilm control, using Pseudomonas aeruginosa PAO1 as a model microorganism. The NO treatment involved the injection of NONOates (NO donor compounds) into mature biofilms, while QQ was implemented by immobilizing QQ bacteria (Escherichia coli TOP10-AiiO or Rhodococcus sp. BH4) in alginate or polyvinyl alcohol/alginate beads to preserve the QQ activity. When AiiO and BH4 beads were applied together with (Z)-1-[N-(3-aminopropyl)-N-(n-propyl) amino] diazen-1-ium-1,2-diolate (PAPA NONOate), they achieved higher biofilm reduction compared to their individual applications. These findings highlight the significant potential of combining QQ and NO technologies for effective biofilm control across a variety of processes that require enhanced biofilm inhibition.
ARTICLE | doi:10.20944/preprints202308.0183.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: bacterial diversity; gut microbiota; prolactin receptor; lactation; weaning
Online: 2 August 2023 (08:46:06 CEST)
Maternal milk supports offspring development by providing microbiota, macronutrients, micronutrients, immune factors, and hormones. The hormone prolactin (PRL) is an important component of milk with protective effects against chronic non-communicable diseases (NCDs). Because maternal milk regulates microbiota composition and microbiota protect against NCDs, we aimed to investigate whether PRL regulates gut microbiota in newborn mice. 16SrRNA sequencing of feces and bioinformatics analysis were performed to evaluate gut microbiota in mice null for the PRL receptor (Prlr-KO) at the onset of weaning (postnatal day 21). The normalized colon and cecal weights were higher and lower, respectively, in Prlr-KO mice relative to wild-type mice (Prlr-WT). Relative abundance (Simpson Evenness Index), phylogenetic diversity, and bacterial concentration in gut contents were lower in the absence of the PRL receptor. Eleven bacteria species, out of 470, differed between Prlr-KO and Prlr-WT mice with two bacterial genera (Anaerotruncus and Lachnospiraceae) related to NCD development being the most common in Prlr-KO. Furthermore, a higher metabolism of terpenoids and polyketides was predicted in Prlr-KO mice compared to Prlr-WT mice; these metabolites have antimicrobial properties and are present in microbe-associated pathogenicity. In summary, the absence of the PRL receptor changes intestinal microbiota composition, resulting in lower microbiota abundance and richness, which could contribute to NCD development.
ARTICLE | doi:10.20944/preprints202211.0382.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Bacillus; bacterial antagonist; genome sequence; antimicrobial peptide; biologicals
Online: 21 November 2022 (07:43:01 CET)
Plant diseases are among the major factors affecting plant productivity. Biological control of plant diseases is preferred over chemical control as it is environment-friendly, cost-effective, and sustainable. Among many microbes capable of providing biological control of plant diseases, probiotic Bacillus species are most promising as they can survive in adverse conditions, provide plants with a wide range of benefits including protection from phytopathogens. Wheat blast caused by Magnaporthe oryzae Triticum pathotype (MoT) has emerged as a potential threat to global wheat production. Due to unreliability of fungicides and limited cultivar resistance, we aimed to screen and identify potential antagonist bacteria collected from internal tissues of rice and wheat seeds to determine their in vitro and in vivo inhibitory effects against MoT. Dual culture and seedling assays were performed to evaluate the efficacy of probiotic bacteria. Out of 170 bacterial isolates, three bacteria (BTS-3, BTS-4, and BTLK6A) were screened as potential antagonists against MoT in vitro. Artificial inoculation at the seedling stage showed that the isolates BTS-4, BTS–3, and BTLK6A reduced 89, 88, and 85% of wheat blast disease severity, respectively, compared to mock-inoculated control. The bacterial isolates were identified as Bacillus subtilis (BTS-3) and B. velezensis (BTS-4 and BTLK6A) through genome phylogeny. The whole genome sequence of these three bacterial strains decoded a number of orthologs to intrinsic genes of antimicrobial peptides, antioxidant defense enzymes, cell wall degrading enzymes, compounds involved in the induction of systemic resistance (ISR) in host plants, and volatile compounds to make them promising biologicals to control MoT in wheat. Combined data of in vitro and in vivo along with genome analysis suggest that Bacillus spp. suppress the destructive wheat blast disease likely through antibiosis and ISR in the host plants. Further field evaluation and characterization of antimicrobial compounds are needed for a better understanding of the mode of action and practical recommendation of these bacteria for wheat blast control in the farmers’ fields.
REVIEW | doi:10.20944/preprints202209.0048.v1
Subject: Chemistry And Materials Science, Chemical Engineering Keywords: removal; PAHs; heavy metals; marine sponges; bacterial consortium
Online: 5 September 2022 (07:43:34 CEST)
Toxic materials in waste generally contain several components of global trending pollutant categories, especially PAHs and heavy metals. Bioremediation technology for managing waste utilizing microorganisms (bacteria) has not been fully capable of breaking down these toxic materials simple and environmentally friendly chemical products. This study examines the potential application of a marine sponge symbiont consortium with high performance and efficiency in removing PAHs and heavy metal contaminants. The method is carried out through a review of some related research articles by the author and published by other re-searchers. The study results concluded that bioremediation technology development GTP, can be carried out to improve remediation efficiency. Several types of marine sponge symbiont bacteria, hydrocarbonoclastic (R-1), metalloclastic (R-2), and metallohydro-carbonoclastic (R-3), have the potential to be applied to improve the removal performance of waste. Bacterial screening be done to find and categorize R-1 bacteria, R-2; R-3 to remediate GTP. Develop of R-1 bacteria, R-2; R-3 forms of the mobile formulation are needed in the future. A crystalline consortium of bacteria preparations is needed so that they can be quickly mobilized to locations exposed to GTP. Marine sponge symbiont bacteria be traced mainly to marine sponges whose body surface is covered with mucus.
REVIEW | doi:10.20944/preprints202103.0424.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: vaginal probiotics; reproductive dysbiosis; bacterial vaginosis; VVC; IVF
Online: 16 March 2021 (12:28:32 CET)
The use of probiotics in reproductive-related dysbiosis is an area of continuous progress due to the growing interest from clinicians and patients suffering recurrent reproductive microbiota disorders. An imbalance in the natural colonization sites related to reproductive health: vaginal, cervicovaginal, endometrial and also pregnancy-related altered microbiota could play decisive role in reproductive outcomes. Oral and vaginal administrations are in continuous discussion regarding the clinical effect pursued, but probiotics as oral supplement therapy is the route administration better studied. To complement and summarise with qualitative and quantitative information of vaginal probiotics clinical studies, the main objective of this work was to retrieve the standardised protocols commonly used and their microbiota modulation capacities. The studies selected were related to treat bacterial vaginosis (BV) as the most commonly disorder, few studies on vulvovaginal candidiasis (VVC) and also administration to stabilise microbiota before in vitro fertilisation (IVF). Probiotic doses administered were similar to oral probiotics protocols, ranging from ≥ 107 CFU/day to 2.5 x 1010 CFU/day, and variable regarding posology duration from 1 day to 12 weeks, being 1 week commonly applied. Moderate modulation was achieved regarding the relative abundance decrease of abnormal microbiota, coinciding with parallel increase in Lactobacillus species.
ARTICLE | doi:10.20944/preprints202001.0069.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: DEHP; biochemical pathways; immobilization; MBR; bacterial community dynamics
Online: 9 January 2020 (05:00:48 CET)
A bacterial strain that could effectively degrade DEHP was isolated from the activated sludge and identified as Bacillus sp. by DNA sequencing. The biochemical degradation pathway of DEHP was further analyzed by GC-MS, and the results showed that DEHP was first decomposed into phthalates (DBP). Diuretic sylycol (DEP) was then generated, and phthalates (PA) were generated by a continuous de-ehelateization reaction. Phthalic acid (PA) was oxidized, dehydrogenated, and decarboxylated into protocatechins. Protocatechins enter the TCA cycle through orthotopic ring opening. To enhance DEHP degradation, sodium alginate and calcium chloride were used as embedding and cross-linking materials, and the strain was immobilized. The immobilization conditions were optimized via an orthogonal experiment, and the results showed that the optimal immobilization conditions were SA mass fraction of 4%, CaCl2 mass fraction of 5%, ratio of bacteria to SA of 1:1, and the crosslinking time of 6 hours. The immobilized bacteria agent was further applied to MBR systems. The results showed that the removal rate of DEHP (5mg/L) in the system by immobilized bacteria was 91.9%, which is significantly higher than that of free bacteria. The 3, 4-dioxygenase gene and microbial community dynamics were analyzed by q-PCR and Illumina Miseq sequencing. The q-PCR results showed that the number of copies of 3, 4-dioxygenase gene in the immobilized system was significantly higher than that of free bacteria. Illumina Miseq sequencing results showed that Micromonospora, Rhodococcus, Bacteroides and Pseudomonas were the dominant generas in the MBR system. The analysis of bacterial community structure indicated that immobilization technology had a positive impact on the system stability. The results implied that this immobilized technique had potential applications in DEHP wastewater treatment.
REVIEW | doi:10.20944/preprints201708.0093.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: bacterial pathogens; host-pathogen interaction; infection biology; omics
Online: 27 August 2017 (11:18:27 CEST)
By providing useful tools to study host-pathogen interactions, next-generation omics has recently enabled the study of gene expression changes in both pathogen and infected host simultaneously. However, since great discriminative power is required to study pathogen and host simultaneously throughout the infection process, the depth of quantitative gene expression profiling has proven to be unsatisfactory when focusing on bacterial pathogens, thus preferentially requiring specific strategies or the development of novel methodologies based on complementary omics approaches. In this review, we focus on the difficulties encountered when making use of omics approaches to study bacterial pathogenesis. Besides, we review different omics strategies (i.e. transcriptomics, proteomics and secretomics) and their applications for studying interactions of pathogens with their host.
ARTICLE | doi:10.20944/preprints202311.1328.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: deoxycholic acid; blood pressure; cardiac output; vasodilatation; bacterial metabolites
Online: 21 November 2023 (13:19:07 CET)
Background: Deoxycholic acid (DCA) is a secondary bile acid produced by gut bacteria. Its serum concentration increases in cardiovascular disease (CVD). We hypothesized that DCA may affect hemodynamic parameters in rats. Methods: The concentration of DCA in systemic blood was measured with liquid chromatography coupled with mass spectrometry. Arterial blood pressure (BP), heart rate (HR) and echocardiographic parameters were evaluated in anesthetized, male, 3-4-month-old Sprague-Dawley rats administered intravenously (IV) or intracerebroventricularly (ICV) with investigated compounds. Mesenteric artery (MA) reactivity was tested ex vivo. Results: The baseline plasma concentration of DCA was 0.24 ± 0.03 mg/l. The oral antibiotic treatment produced a large decrease in the concentration. Administered IV, the compound increased BP and HR in a dose-dependent manner. DCA also increased heart contractility and cardiac output. None of the tested compounds: prazosin (an alpha-blocker), propranolol (beta-adrenolytic), atropine (muscarinic receptor antagonist), glibenclamide (K-ATP inhibitor) or DY 268 (FXR antagonist), glycyrrhetinic acid (11HSD2 inhibitor) significantly diminished the DCA-induced pressor effect. ICV infusion did not exert significant HR or BP changes. DCA relaxed MAs. Systemic vascular resistance did not change significantly. Conclusions: DCA increases BP by increasing cardiac output. As a bioactive gut bacteria-derived metabolite, DCA may co the interaction between gut microbiota and the host’s circulatory system.
REVIEW | doi:10.20944/preprints202306.1873.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Bacterial Extracellular Vesicles; Therapeutics; Neurodegenerative Disease; Alzheimer's Disease; Nanocarriers
Online: 27 June 2023 (09:27:15 CEST)
Bacterial Extracellular Vesicles (BEVs) generated from the bacteria has high feasibility of intracellular interactions with other cells, can be used as a cargo to deliver any therapeutic substances like monoclonal antibodies, proteins, plasmids, siRNA and small molecules for the treatment of neurodegenerative diseases (NDs). BEVs have a high ability for delivering therapeutic molecules across the blood-brain barrier to treat Alzheimer's Disease (AD) via various mechanisms. In this review, we have sum up in-depth research details of the role and advancement of BEVs in NDs, AD and its Therapeutics. Moreover, details about offensive and defensive functions of BEVs in ND pathogenesis and examine the critical BEV networks in the microbiome-gut-brain axis and their role in neurodegenerative disorders. Additionally determining the roles of BEVs in the neuroimmune system and their interaction with neurodegenerative disorders and exploring the risk factors of BEVs in the autophagy-lysosomal pathway and their possible effects on neurodegenerative disorders are summarised in detail. In conclusion, this review seeks to contribute to a better understanding of the potential function of BEVs in NDs and to identify new therapeutic intervention strategies.
REVIEW | doi:10.20944/preprints202305.2196.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: Nanocellulose; Cellulose Nanofibrils; Cellulose Nanocrystals; Bacterial Nanocellulose; Energy Storage
Online: 31 May 2023 (08:14:34 CEST)
Primary materials supply is the heart for engineering and sciences; depletion of natural resources and an increase in the human population by a billion in 13 to 15 years pose a critical concern on the sustainability of the materials. Therefore, functionalizing renewable materials, such as nanocellulose, possibly exploiting its properties for various practical applications, has been undertaken worldwide. Nanocellulose has emerged as a dominant green natural material with attractive and tailorable physicochemical properties, renewable, sustainable, biocompatibility, and tunable surface properties. Nanocellulose is derived from cellulose, the most abundant polymer in nature with remarkable properties of nanomaterials. This article provides a comprehensive overview of the methods used for nanocellulose preparation, structure-property and processing-property correlations, and the application of nanocellulose and its nanocomposite materials. This article differentiates the classification of nanocellulose, provides a brief account of the production methods that have been developed for isolating nanocellulose, highlights a range of unique properties of nanocellulose that have been extracted from different kinds of experiments and studies; and elaborates on nanocellulose potential applications in various areas. The present review is anticipated to provide the readers regarding the progress and knowledge related to nanocellulose. Pushing the boundaries of nanocellulose further into cutting edge applications will be of particular interest for the future, especially as cost-effective commercial sources of nanocellulose continue to emerge.
REVIEW | doi:10.20944/preprints202305.0732.v1
Subject: Medicine And Pharmacology, Pulmonary And Respiratory Medicine Keywords: chronic bacterial broncitis; airways disease; biofilms; microbiome; COPD; bronchiectasis
Online: 10 May 2023 (10:13:54 CEST)
This manuscript is aimed at encouraging those interested in biofilms and their effects on microbial communities to view the study of chronic airways disease as one of the most challenging and potentially rewarding areas to focus on. To do this it is necessary to review how we have reached 2023 having made so little progress. It is more than two hundred years ago since the term bronchitis was proposed to describe diseases affecting the airways rather than the respiratory zone of the lungs. The main histological features were described in Laennec’s text of 1819. By the mid C20th it was recognised that the two great drivers of chronic respiratory symptoms were inhaled toxins and chronic bacterial infections. The widespread availability of antibiotics in subsequent years had a dramatic impact on mortality from pneumonia, greatly reduced the prevalence of chronic symptoms after acute lower respiratory tract infections, transformed the lives of many with bronchiectasis and appeared to play a major role in the dramatic fall in prevalence of bronchiectasis. Unfortunately, during the following 70 years the importance of dealing with a chronic bacterial bronchitis was largely forgotten. While two artificial diseases ‘COPD’ and ‘bronchiectasis’ have been the subject of numerous guidelines, chronic bacterial bronchitis has been out in the cold. Antibiotics have in theory been reserved for those with established damage in the form of bronchiolitis and impaired lung function as defined by an arbitrary FEV1/FVC ratio and even then there is a disconnect with a minimum of 2 weeks being prescribed for exacerbations of bronchiectasis and the use of long term inhaled and oral macrolides frequently being advocated while a 5 day course is reserved for an exacerbation in a patient with COPD. The loss of focus on the role of antibiotics has a number of causes – a desire to ration antibiotic as part of ‘antibiotic stewardship’, the potential cost of treatment, the failure to ‘cure’ patients with chronic bronchitis and the difficulty in dealing with a disease whose morbidity at any given time can range from a mild cough and production of phlegm in the morning with no obvious impact on daily function to troublesome cough, sputum production and significant ill health. This was compounded by the vagaries of culture based diagnosis and the observation that more than one potential pathogen was often present. As a result chronic bacterial bronchitis was relegated to the ‘too hard to deal with’ box and many of the lessons of the past were forgotten. Revisiting the field from the perspective of current understanding of bacterial behaviour in biofilms and how these alter the resident microbiota of the airways should ensure that a chronic bacterial bronchitis returns to centre stage in order to minimise respiratory morbidity and mortality. This review charts the history of our understanding and mis-understanding of the role of chronic bacterial bronchitis in airways disease and the pernicious effect of language in helping to ensure that this common and important condition became the elephant in the room. Focusing on the nature of chronic bacterial bronchitis is essential if we are to find ways of identifying it accurately and treat it effectively – new approaches will be extremely slow unless we recognise its importance and the challenges it poses.
ARTICLE | doi:10.20944/preprints202302.0431.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: nanocomposites; bacterial nanocellulose; microporosity; biomineralization process and bone regeneration
Online: 27 February 2023 (02:29:23 CET)
Bacterial nanocellulose (BNC) surface has a negative charge that allows the adsorption of calcium ions to initiate the nucleation of different calcium phosphate phases. The aim of this study was to investigate different methods of mineralization on three-dimensional microporous bacterial nanocellulose, to mimetize the composition, structure, and biomechanical properties of natural bone. To generate 3D microporous biomaterial, the porogen particles were incorporated during the BNC fermentation with the strain Komagataeibacter medellinensis. Calcium phosphates (CPs) were deposited on BNC scaffolds by five alternating immersing cycles with calcium and phosphate solutions. Scanning electron microscopy micrograph showed that the scaffolds have different pore sizes, between 70 and 350 µm, but the porous interconnectivity was affected by the biomineralization method and time. The crystals on the BNC surface are shown to be rod-shaped with a calcium phosphate ratio similar to that of immature bone, increasing from 1.13 to 1.6 with cycle numbers. The main mineral phases obtained by X-ray diffraction were Octacalcium Dihydrogen Hexakis (phosphate (V)) Pentahydrate (OCP). In vitro cell studies showed good cellular adhesion and higher cell viability to 95% in all the scaffolds. Osteogenic differentiation of human bone marrow mesenchymal stem cells on the scaffolds was evaluated by bone expression markers like alkaline phosphatase, osteocalcin, and osteopontin. In conclusion, it is possible to prepare 3D BNC scaffolds with controlled microporosity, which could allow osteoblast adhesion, proliferation, and differentiation.
ARTICLE | doi:10.20944/preprints202210.0048.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Lead; Field trial; Phytostabilization; Phytomanagement; Aromatic plants; Bacterial community
Online: 5 October 2022 (17:51:14 CEST)
This field study aimed to assess the base line conditions of a long-term polluted shooting range in Argentina polluted with 428 mg kg-1 lead (Pb), to evaluate the establishment and development of Helianthus petiolaris plants and address the efficacy of the phytomanagement strategy through: i) element accumulation in plant tissues; ii) rhizosphere bacterial diversity changes by Illumina Miseq™ and iii) floral water and essential oil yield, composition and element concentration by GC-MS and ICP. After one life cycle growing in the polluted sites, in the roots of Helianthus petiolaris plants Pb concentration was between 195 and 304 mg kg-1 Pb. Only a limited fraction of the Pb was translocated to the aerial parts. The predominance of the genus Serratia in the rhizosphere of Helianthus petiolaris plants cultivated in the polluted sites and the decrees of the essential oil yield were some effects significantly associated with soil Pb concentration. No detectable Pb concentration was found in the floral water and essential oil obtained. Extractable Pb concentration in the soil reduced between 28-45 % after the harvest.
ARTICLE | doi:10.20944/preprints202209.0143.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Salmonella; novel antibacterial agents; cannabidiol; co-therapy; bacterial genetics
Online: 12 September 2022 (09:55:22 CEST)
New generation antibiotics are needed to combat the development of resistance to antimicrobials. One of the most promising new classes of antibiotics is cannabidiol (CBD). It is a non-toxic and low-resistance chemical that can be used to treat bacterial infections. The antibacterial activity of Cannabis sativa L. byproducts, specifically CBD, has been of growing interest in the field of novel therapeutics. As research continues to define and characterize the antibacterial activity that CBD possesses against a wide variety of bacterial species it is important to examine potential interaction between CBD and common therapeutics such as broad-spectrum antibiotics. Here, we show that CBD-antibiotic co-therapy can effectively fight S. typhimurium via membrane integrity disruption. This research serves to examine the potential synergy between CBD and three broad-spectrum antibiotics for potential antibiotic-CBD co-therapy. In this study, we reveal that Salmonella typhimurium (S. typhimurium) growth is inhibited at very low dosages of CBD-antibiotic. This interesting finding demonstrates that CBD and CBD-antibiotic co-therapies are viable novel alternatives to combating Salmonella typhimurium.
ARTICLE | doi:10.20944/preprints202208.0191.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: bacterial genomics; de novo assembly; Oxford Nanopore Technologies; Snakemake
Online: 10 August 2022 (04:37:01 CEST)
With the advancement of long-read sequencing technologies and their more widespread use for bacterial genomics, several methods for generating genome assemblies from error-prone long reads have been developed. These are complemented by various tools for assembly polishing using either long reads, short reads, or reference genomes. End users are therefore left with a plethora of possible combinations of programs for obtaining a final trusted assembly. Hence, there is also the need for measuring completeness and accuracy of such assemblies, for which, again, several evaluation methods implemented in various programs are available. In order to automatically run all these programs, I developed two workflows for the workflow management system Snakemake for bacterial genome assembly and evaluation of assemblies, which provide end users with an easy-to-run method for both tasks. The workflows are available as open source software under the MIT license at https://github.com/pmenzel/ont-assembly-snake and https://github.com/pmenzel/score-assemblies.
ARTICLE | doi:10.20944/preprints202112.0127.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: plant pathogenic bacterium; phage; bacterial wilt; biological control; lyophilization
Online: 8 December 2021 (14:12:11 CET)
Ralstonia solanacearum is a pathogen that causes bacterial wilt producing severe damage in staple solanaceous crops. Traditional control has low efficacy and/or environmental impact. Recently, the bases of a new biotechnological method by lytic bacteriophages vRsoP-WF2, vRsoP-WM2 and vRsoP-WR2 with specific activity against R. solanacearum were established. However, some aspects remain unknown, such as the survival and maintenance of the lytic activity after submission to a preservation method as the lyophilization. To this end, viability and stability of lyophilized vRsoP-WF2, vRsoP-WM2 and vRsoP-WR2 and their capacity for bacterial wilt biocontrol have been determined against one pathogenic Spanish reference strain of R. solanacearum in susceptible tomato plants in different conditions and making use of various cryoprotectants. The assays carried out have shown satisfactory results with respect to the viability and stability of the bacteriophages after the lyophilization process, maintaining high titres throughout the experimental period, also with respect to the capacity of the bacteriophages for the biological control of bacterial wilt, controlling this disease in more than 50% of the plants. The results offer good prospects for the use of lyophilization as a conservation method for the lytic bacteriophages of R. solanacearum in view of their commercialization as biocontrol agents.
ARTICLE | doi:10.20944/preprints202111.0348.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Agar over assay; bacterial inhibition; Neisseria gonorrhoeae; Neisseria mucosa
Online: 19 November 2021 (12:23:16 CET)
Antibiotic-sparing treatments are required to prevent the further emergence of anti-microbial resistance in Neisseria gonorrhoeae. Commensal Neisseria species have previously been found to inhibit the growth of pathogenic Neisseria species. For example, a previous study found that 3 out of 5 historical isolates of Neisseria mucosa could inhibit the growth of N. gonorrhoeae. In this study, we used agar overlay assays to assess if 24 circulating and historical isolates of Neisseria mucosa could inhibit the growth of 28 circulating and historical isolates of N. gonorrhoeae. Although pitting around each colony of N. mucosa created an optical illusion of decreased growth of N. gonorrhoeae, we found no evidence of inhibition (n=24). In contrast, positive controls of Streptococcus pneumoniae and Escherichia coli demonstrated a strong inhibitory effect against the growth of N. gonorrhoeae.
REVIEW | doi:10.20944/preprints202101.0517.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Gram-negative bacterial; Metabolite transporter; pathways; metabolic engineering approaches
Online: 25 January 2021 (15:49:13 CET)
Metabolite transport across cellular membranes is a key feature of living organisms. Specialized proteins or protein complexes mediate such transport processes and are accessible to genetic engineering approaches. This special issue will reflect on the different transport between cellular compartments. It will provide an overview about different transporter classes and metabolic engineering approaches in different organisms ranging from Bacteria to Eukarya. The transport mechanisms energetics of these compounds were thought little of, and most consideration was given to the designing of metabolic pathways. Gram-negative microbes discharge a wide scope of proteins whose capacities incorporate biogenesis of organelles, for example, pilli and flagella, supplement securing, destructiveness, and efflux of medications and different poisons. Six particular emission frameworks have been appeared to intervene protein send out through the inward and external layers of Gram-negative microbes. These pathways are exceptionally monitored all through the Gram-negative bacterial species. In Gram-positive microscopic organisms, discharged proteins are usually moved across the single layer by the Sec pathway or the two-arginine (Tat) pathway. Recently efforts focused on transporter and metabolite engineering, visualize the improvement and enhancement of microbial cell to pass such metabolites these metabolite carrier proteins are inserted into the inner membrane of mitochondria across the inner membrane, specialized carrier proteins are necessary that mediate the transport into and out of the mitochondrial matrix. Two main strategies for metabolic engineering in plants: the introduction of genes encoding new enzymes and the use of TFs controlling specialized metabolic pathways
ARTICLE | doi:10.20944/preprints202007.0092.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Bacterial resistance; Animal venom; Purification; Antibacterial and antibiofilm activity
Online: 6 July 2020 (04:00:43 CEST)
Introduction: Bacterial resistance is a worldwide public health problem, requiring new therapeutic options. An alternative approach to this problem is the use of animal toxins, such as phospholipases (PLA2) isolated from snake venom, which have important biological activities. Bothrops erythromelas is one of the snake species in the Northeast of Brazil that attracts great medical-scientific interest. Here we aimed to purify and characterize a PLA2 from B. erythromelas, searching for heterologous activities against bacterial biofilm. Methods: Venom extraction and quantification were followed by RP-HPLC in C18 column, MALDI-ToF mass spectrometry and sequencing by Edman degradation. All experiments were monitored by specific activity using 4-nitro-3 (octanoyloxy) benzoic acid (4N3OBA) substrate. In addition, hemolytic tests and anti-bacterial tests including action against Escherichia coli, Staphylococcus aureus and Acinetobacter baumannii, were carried out. Moreover, tests of antibiofilm action against A. baumannii were also performed. Results: PLA2, after one purification step, presented 31 N-terminal amino acid residues, and molecular weight of 13656.4 Da with enzymatic activity confirmed in 0.06 µM concentration. Antibacterial activity against S. aureus (IC50 = 30.2 µM) and antibiofilm activity against A. baumannii (IC50 = 1.1 µM) were observed. Conclusions: This is the first time that PLA2 purified from B. erythromelas venom has appeared as an alternative candidate in studies of new antibacterial medicines.
ARTICLE | doi:10.20944/preprints201804.0349.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: bacterial infections; sensitivity; specificity; immature granulocytes; Latvia; child; sepsis
Online: 27 April 2018 (06:09:47 CEST)
Background: Detection of small proportion of serious bacterial infections (SBI) with potentially life threating course in a large group of children with fever admitted to emergency department (ED) is still complicated. Measurement of immature granulocytes (IG) percentage may be used as a marker of bacterial infections. The aim of the study was to evaluate whether the IG percentage is a useful additional predictive marker of SBI. Methods: This study included 258 children with febrile infections admitted to the ED. Clinical follow-up, microbiological and radiological tests were used as reference standards for the definition of SBI. Study population was categorized into two groups: (i) infected patients with no suspicion of SBI (n = 75); (ii) patients with suspicion of SBI (n = 183). IG percentage, white blood cell count (WBC) and C-reactive protein (CRP) levels were analyzed from the first routine blood samples at hospital admission. Results: A statistically significant difference in IG percentage levels was observed in children with SBI and those without - the mean IG percentage was 1.2% for the SBI group, 0.3% for those without SBI. The cutoff level of IG percentage to predict SBI was 0.45 (84% specificity, 66% sensitivity, 90% positive predictive value). We combine variables and evaluate their additive values. The sensitivity of WBC to detected SBI improved from 74% to 85% when IG percentage was added to the prediction models. When CRP, WBC and IG percentage were combined, the sensitivity to predict SBI increased to 93%, the specificity to 86%. (95% CI 77–93%). Receiver operator characteristic analysis to predict SBI showed an area under the curve (AUC) of 0.80 for IG percentage. Conclusion: Addition of IG percentage to traditionally used markers of SBI as WBC and CRP may help to identify children with serious bacterial infections. Furthermore IG percentage can be rapidly obtained from the traditional full blood count without any extra sampling and costs.
ARTICLE | doi:10.20944/preprints201711.0202.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: bacterial inactivation; drinking water; electromagnetic fields; electroporation; Escherichia coli
Online: 30 November 2017 (11:22:25 CET)
Bacteria play a key role in both human health and disease. One of the most prevalent harmful bacteria is E. coli which is responsible for several illnesses ranging from diarrhea, stomach cramp and fever. In this work we explore the application of moderate electric or magnetic fields for treating deionized water that is contaminated with E. coli. We found that moderate alternating electric (AC) fields (10 V/cm to 1kV/cm) and moderate static magnetic fields (10 to 65 mT) can significantly inactivate E. coli by up to 90% or more. This provides the possibilities of developing a low cost and a practical bacteria inactivation technique using electric or magnetic fields.
ARTICLE | doi:10.20944/preprints201701.0071.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: C-type lectin; agglutination; CRD; bacterial detection; E. coli
Online: 13 January 2017 (13:17:13 CET)
Lectins are carbohydrate-interacting proteins playing a pivotal role in multiple physiological and developmental aspects of all organisms. They can specifically interact with different bacterial and viral pathogens through the carbohydrate-recognition domains (CRD). In addition, lectins are also of biotechnological interest because of their potential use as biosensor for capturing and identification of bacterial species. In this work, we have characterized the bacterial agglutination properties of three C-type lectins from the Lepidoptera Spodoptera exigua. One of these lectins, BLL2, was able to agglutinate cells from a broad range of bacterial species at an extremely low concentration, becoming a very interesting protein to be used as biosensor or other biotechnological applications involving bacterial capturing.
ARTICLE | doi:10.20944/preprints202309.1574.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: Lactobacillus bulgaricus; growth media; nitrogen source; starter culture; bacterial enumeration
Online: 25 September 2023 (12:34:21 CEST)
The objective of the present study was to develop and optimize an efficient growth media for Lactobacillus delbrueckii ssp. bulgaricus, an essential dairy starter culture, uses plant-based nitrogen sources. The composition of the de Man, Rogosa, and Sharpe (MRS) culture medium was modified, and the nitrogen content was replaced by alternative nitrogen sources X-Seed N7 and N5 in various blends of 3% and 1.5%. Results showed that bacterial growth was higher with the N7 and N5 nitrogen source blends at 3% and 1.5%. Similarly, the optical densities of the L. bulgaricus strains were higher in the N7 and N5 blends (1.5/3%) compared to the MRS medium. Although there was no significance in bacterial counts for both the MRS and the N7 and N5 media, a significant difference between the control medium and the optimized growth media was noted. Our results thus suggest that the alternative nitrogen sources X-Seed N7 and N5 can substantially support the growth of lactic acid bacteria as shown with L. bulgaricus. Moreover, the presence of complex nitrogen sources rich in free nucleotides, amino acids, and peptides enhanced L. bulgaricus growth. Our results support the development of cost-effective and plant-based growth media for LAB cultures and potential benefits to the food and dairy industries. Additional research is warranted to improve buffering capacity for higher cell counts.
ARTICLE | doi:10.20944/preprints202309.1302.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Bacterial blight; Xanthomonas oryzae pv. oryzae; molecular characterization; resistance genes
Online: 19 September 2023 (11:00:55 CEST)
In Benin, Xanthomonas oryzae pv. oryzae (Xoo) causing bacterial blight (BLB) was first described in 2013 on wild rice Oryza longistaminata. No studies have been conducted on Beninese Xoo strains and resistant rice varieties. The aim of this study is to check whether Xoo has already spread to cultivated varieties and to screen some rice accessions for the main resistance genes detection. To achieve this aim, rice leaves showing typical BLB symptoms were collected from various rice fields in Benin and analyzed by PCR to identify Xoo-specific sequences. In addition, seventy-five rice accessions were examined to identify Xoo resistance genes. The results showed that Xanthomonas oryzae (Xo) had been identified in Banikouara and Malanville. In addition, Sphingomonas sp was detected in several rice fields. A Xo-Sphingomonas Sp co-infection was also noted. 47 of 75 rice accessions examined (62.66%) carried Xoo resistance genes with 3 (4%) and 40 (53.33%) of xa5 and Xa21 respectively. None of the accessions had neither Xa7 nor Xa13 resistance genes. Three accessions had both xa5 and Xa21 genes. In addition, the rice isogenic lines IRBB60 and IRBB21used as positive controls, were found to be susceptible. These results indicate that Xo has evolved from a wild rice to cultivated varieties in northern Benin. Consequently, a varietal improvement program must be implemented with varieties having resistance genes to prevent a BLB pandemic in Benin.
ARTICLE | doi:10.20944/preprints202308.1447.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Silage additives; Condensed tannin; Fermentative quality; Bacterial modulation; silage quality
Online: 22 August 2023 (03:44:48 CEST)
Maize silage is produced to alleviate forage shortage on dairy animals, particularly during the dry season. Microorganisms play a significant role in silage fermentation and thus determine the silage quality. Therefore, modulation of microorganisms in silage may help prohibit undesired bacteria and improve silage quality. Hence, this study evaluated the effects of tannin extract as an additive on fermentative quality, aerobic stability and microbial composition of maize silage. Therefore, a mini-silo experiment of maize with five treatments was conducted for 75 days. The results showed that additives modulate silage microorganisms. In addition, tannin extract reduced certain silage bacteria while promoting others. However, this is without affecting the silage’s fermentative quality and aerobic stability. All silage fermented well with a pH below 4.2. Tannin extract improved dry matter recovery of silage while reducing silage weight loss. Furthermore, tannin extract suppressed the establishment of undesired bacteria, such as genera Dysgonomonas, Gluconacetobacter and Clostridium, while promoting desirable bacteria, such as genera Lactobacillus and Weissella, which attributed to silage quality. Therefore, it is concluded that tannins can be strategically used as silage additives to modulate microbial composition of silage and improve silage quality by promoting the dominance of desirable bacteria in silage.
REVIEW | doi:10.20944/preprints202307.1941.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: Stimuli-triggered nano-systems; hybrid nano-systems; biomimetics; bacterial infections
Online: 27 July 2023 (13:06:30 CEST)
In recent years, antimicrobial resistance in many human pathogens has become a serious health concern. Since infections with resistant pathogens cannot be treated with traditional antimicro-bial drugs, new strategies are necessary to fight bacterial infections. Hybrid nano-systems may provide a solution to this problem, by combining multiple mechanisms for killing bacteria to synergistically increase the effectiveness of the antimicrobial treatment. In this review, we high-light recent advances in the development of hybrid nano-systems for the treatment of bacterial infections. We discuss the use of hybrid nano-systems for combinational therapy, focusing on various triggering mechanisms for drug release and the development of biomimetic nanomateri-als. We also examine inherently antimicrobial nano-systems and their uses in preventing infec-tions due to wounds and medical implants. This review summarizes recent advances and pro-vides insight into the future development of antimicrobial treatments using hybrid nanomateri-als.
ARTICLE | doi:10.20944/preprints202305.0109.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Activity; beneficial traits; bacterial count; inoculation; rhizosphere; salinity; salt tolerance
Online: 3 May 2023 (07:31:47 CEST)
Soil salinity is one of the most serious problems for achieving better crop growth and yield. The study was conducted to isolate, characterize and screen salt tolerant microbes from spinach grown in saline soils. The efficient salt tolerant microbes were characterized for beneficial traits such as nitrogen fixation, phosphate solubilization, indoleacetic acid (IAA), biofilm production, catalase and antagonistic activities, salt tolerance and optimization of bacterial fermentation. Molecular identification of potential microbes was done by 16S rRNA gene sequencing. The collected soil samples were moderately to strongly saline, alkaline in nature, low in N and P while adequate in K and Ca concentration. A total of 17 salt tolerant bacteria differing in colony and cell morphology were characterized. All isolated rhizobacterial microbes had capability to biosynthesize phytohormone IAA, 14 were able to fix atmospheric N2, 11 microbes solubilized inorganic P, 10 produced biofilm and 15 were positive in catalase activity. The isolated rhizobacteria showed salt tolerance up to 10 % induced salinity, only six microbes tolerated salt concentration of 12.5% however, none of any rhizobacteria remained viable at 15% NaCl amended media plates. The two potential salt tolerant microbes (NIA SP-6 & NIA SP-11) were screened and found for optimum growth curve and fermentation at pH 7.0 after 48 hrs of incubation period. Both potential microbes were identified as Enterobacter cloacae (NIA SP-06) and Bacillus safensis (NIA SP-11). Hence, it can be concluded that isolated salt tolerant rhizobacterial microbes have potential for beneficial traits and have ability for salt tolerance under saline conditions.
ARTICLE | doi:10.20944/preprints202304.0179.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Acmella oleracea; Anti-oxidant; In vitro; Anti-bacterial; Methanol extract
Online: 11 April 2023 (03:09:50 CEST)
Acemella oleracea is known as toothache plant belongs to the family of Asteraceae. It is treated as a medicinal remedy like tuberculosis, illness, cough, rheumatism, and illness. This study was concentrated on the antioxidant, cytotoxic, antimicrobial & thrombolytic activities of methanol extract of Acmella oleracea leaves using in vitro model. The antioxidant activity was estimated as trolox equivalent antioxidant capacity utilizing the DPPH and reducing power tests. The plant extract was tested for its cytotoxic action using a brine shrimp lethality bioassay, thrombolytic activity using clot disruption, and antibacterial activity using a disc diffusion assay technique against four distinct gram-positive and gram-negative bacteria. IC50 value of standard ascorbic acid for DPPH was 7.8µg/ml and the IC50 of the methanol extract of Acmella oleracea leaves was 198.34µg/ml that was moderate effect at all compare with ascorbic acid. Thrombolytic assay of Streptokinase as a positive control showed 88.49% where the extract shows 18.69% lytic activity shows the assay. In this study, the sample of LC50 results of cytotoxicity assay was 1.431 µg/mL which can be treated as less activity. Moreover, the extracts showed low to moderate antibacterial activity against both gram-negative and gram-positive bacterial stains (zone of inhibition-10-26 mm). Vibrio Mimicus bacteria stains exhibited the highest level of activity, with a range of 23 for the diameter of the growth inhibition zone. The current review shows leaf extracts of Acmella oleracea may be used as a source of antioxidant and thrombolytic activity, as well as a significant source of antibacterial and anticancer substances. Further research is required to evaluate in-vivo the pharmacological activity of Acmella oleracea leaves in order to identify the essential metabolites and potential mechanisms.
ARTICLE | doi:10.20944/preprints202303.0534.v1
Subject: Biology And Life Sciences, Other Keywords: Aquifer; Groundwater recharge; Groundwater microbial ecology; Snowmelt; Bacterial communities Perturbation
Online: 31 March 2023 (02:25:18 CEST)
Events of groundwater recharge are associated with changes in the composition of aquifer microbial communities but also abiotic conditions. Modification in the structure of the community can be the result of different environmental condition favoring or hindering certain taxa or due to the introduction of surface-derived taxa. Yet, in both cases, the local hydrogeochemical settings of the aquifer is likely to affect the amount of variation observed. Therefore, in our study, we used 16S rRNA gene sequencing to assess how microbial communities change in response to snowmelt and the potential connectivity between subsurface and surface microbiome in two distinct aquifers located in the region of Vaudreuil-Soulange (Québec, Canada). At both sites, we observed an increase in groundwater level and decrease in temperature following the onset of snow melt in March 2019. Bacterial community composition of each aquifer was significantly different (p < 0.05) between samples collected prior and after groundwater recharge. Furthermore, microbial source tracking results suggested low contribution of surface environments to groundwater microbiome except for months associated with recharge (March 2019 and April 2019). Overall, despite differences in soil permeability between both sites, the period of snow melt was followed by important changes in the composition of microbial communities from aquifers.
ARTICLE | doi:10.20944/preprints202204.0005.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: genome mining; marine environments; molecular networking; bacterial extremophiles; secondary metabolites
Online: 1 April 2022 (10:21:11 CEST)
Understanding extremophiles and their usefulness in biotechnology involves studying their habitat, physiology and biochemical adaptations , as well as their ability to produce biocatalysts, in environments that are still poorly explored. In northwestern Peru, which saline lagoons of marine origin Pacific Ocean, the other site from the coast of Brazil of the Atlantic Ocean. Both environments are considered extreme. The objective of the present work was to compare two different strains isolated from these extreme environments at the metabolic level using molecular network methodology through the Global Natural Products Molecular Social Network (GNPS). In our study, the MS/MS spectra from the network were compared with GNPS spectral libraries, where the metabolites were annotated. Differences were observed in the molecular network presented in the two strains of Streptomyces spp. coming from these two different environments. Within the annotated compounds from marine bacteria, the metabolites characterized for Streptomyces sp. B-81 from Peruvian marshes were lobophorins A (1) and H (2), as well as divergolides A (3), B (4) and C (5). Streptomyces sp. 796.1 produced different compounds, such as glucopiericidin A (6) and dehydro-piericidin A1a (7). The search for new metabolites in underexplored environments may therefore reveal new metabolites with potential application in different areas of biotechnology.
ARTICLE | doi:10.20944/preprints202111.0557.v1
Subject: Biology And Life Sciences, Virology Keywords: Bacterial nomenclature; archaeal nomenclature; genome taxonomy; shotgun metagenomics; Candidatus names
Online: 30 November 2021 (10:53:50 CET)
Thousands of new bacterial and archaeal species and higher-level taxa are discovered each year through the analysis of genomes and metagenomes. The Genome Taxonomy Database (GTDB) provides hierarchical sequence-based descriptions and classifications for new and as-yet-unnamed taxa. However, bacterial nomenclature, as currently configured, cannot keep up with the need for new well-formed names. Instead, microbiologists have been forced to use hard-to-remember alphanumeric placeholder labels. Here, we exploit an approach to the generation of well-formed arbitrary Latinate names at a scale sufficient to name tens of thousands of unnamed taxa within GTDB. These newly created names represent an important resource for the microbiology community, facilitating communication between bioinformaticians, microbiologists and taxonomists, while populating the emerging landscape of microbial taxonomic and functional discovery with accessible and memorable linguistic labels.
ARTICLE | doi:10.20944/preprints202107.0596.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: schizophrenia; neuro-immune; inflammation; physiological stress; bacterial translocation; psychiatry; LPS
Online: 27 July 2021 (09:16:54 CEST)
There is evidence that schizophrenia is characterized by activation of the immune-inflammatory response (IRS) and compensatory immune-regulatory (CIRS) systems and lowered neuroprotection. Studies performed on antipsychotic-naïve first episode psychosis (AF-FEP) and schizophrenia (FES) patients are important as they may disclose the pathogenesis of the disease. However, the interactome of FEP/FES is not well delineated. The aim of the current study was to delineate the characteristics of the protein-protein interaction (PPI) network of AN-FEP and its transition to FES and the biological functions, pathways, and molecular patterns, which are over-represented in FEP/FES. PPI network analysis shows that FEP and FEP/FES are strongly associated with a response to a bacterium, TNF, NFκB, RELA, SP1, JAK-STAT, death receptor and TLR4 signaling, and tyrosine phosphorylation of STAT proteins. Specific molecular complexes of the peripheral immune response are associated with microglial activation, neuroinflammation and gliogenesis. FEP/FES is accompanied by lowered protection against inflammation in part attributable to dysfunctional miRNA maturation, deficits in neurotrophin/Trk, RTK and Wnt/catenin signaling and adherens junction organization. Lowered neuroprotection due to reduced neurotrophin/Trk and Wnt/catenin signaling, and DISC1 expression and multiple interactions between lowered BDNF, CDH1, CTNNB, and DISC1 expression, increase the vulnerability to the neurotoxic effects of immune products including cytokines and complement factors. All pathways or molecular patterns enriched in the interactome of FEP/FES are directly or indirectly affected by LPS. In summary: FEP appears to be triggered by a biotic stimulus (e.g. Gram-negative bacteria) which may induce neuro-immune toxicity cascades especially when anti-inflammatory and neurotrophic protections are deficient.
ARTICLE | doi:10.20944/preprints202105.0556.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Alzheimer’s disease; amyloid-beta; amyloid plaques; bacterial DNA; protein aggregation
Online: 24 May 2021 (10:33:22 CEST)
Alzheimer’s disease is associated with prion-like aggregation of the amyloid β (Aβ) peptide and the subsequent accumulation of misfolded neurotoxic aggregates in the brain. Therefore, it is critical to clearly identify the factors that trigger the cascade of Aβ misfolding and aggregation. Numerous studies have pointed out the association between microorganisms and their virulence factors and Alzheimer’s disease; however, their exact mechanisms of action remain unclear. Recently, we discovered a new pathogenic role of bacterial extracellular DNA, triggering the formation of misfolded Tau aggregates. In this study, we investigated the possible role of DNA extracted from different bacterial and eukaryotic cells in triggering Aβ aggregation in vitro. Interestingly, we found that the extracellular DNA of some, but not all, bacteria is an effective trigger of Aβ aggregation. Furthermore, the acceleration of Aβ nucleation and elongation can vary based on the concentration of the bacterial DNA and the bacterial strain from which this DNA had originated. Our findings suggest that bacterial extracellular DNA might play a previously overlooked role in the Aβ protein misfolding associated with Alzheimer’s disease pathogenesis. Moreover, it highlights a new mechanism of how distantly localized bacteria can remotely contribute to protein misfolding and diseases associated with this process. These findings might lead to the use of bacterial DNA as a novel therapeutic target for the prevention and treatment of Alzheimer’s disease.
ARTICLE | doi:10.20944/preprints202105.0207.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Suture material; Third molar surgery; Surgical wound infection; Bacterial adhesion
Online: 10 May 2021 (15:08:53 CEST)
Background: Selection and application of suture materials, has gained more importance especially with the increasing number of patients seeking oral surgeries. Since lying in a bacterial-filled environment, sutures make the tissue prone to infection. Suture material plays an important role in the reduction of the risk of infection. This study aimed to assess the success rate of an antibacterial suture named Vicryl Plus in preventing bacterial growth in the surgical site of the mandibular third molar. Methods: 27 patients were included in this double-blinded randomized clinical trial study. Surgical Extraction of the mandibular wisdom tooth was done and the incision was managed by randomly using Vicryl Plus and Vicryl sutures. After 7 days, sutures were removed and assessed microbiologically. Predominant species of Streptococcus mutans and Lactobacillus were assessed as well as the total number of colonies on each suture. Results: There was a significant difference between two suture materials in colony number-length ratio of lactobacillus (p-value= 0.031) and total bacterial colonies (p-value=0.016); but not for S. mutans species (p-value=0.201). Conclusion: Antibacterial Vicryl suture can be a useful tool for the reduction in the rate of surgical site infection in high-risk cases and situations.
HYPOTHESIS | doi:10.20944/preprints202104.0516.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: spontaneous regression; tumors; cancer; bacterial therapy; Coley; immunotherapy; hyperthermia; oncology
Online: 19 April 2021 (21:03:16 CEST)
Neither tumor growth nor regression is truly spontaneous, but both may under special circumstances be driven by similar events. We describe a sequence of processes that typically leads to tumor progression but may on occasion inadvertently result in regression. A possible procedure for reducing tumor mass through a controlled intervention is also outlined.
ARTICLE | doi:10.20944/preprints202101.0623.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: depression; neuroimmune; inflammation; oxidative and nitrosative stress; autoimmune; bacterial translocation
Online: 29 January 2021 (13:17:48 CET)
The approach towards myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) remains in a permanent state of crisis with fierce competition between the psychosocial school, which attributes ME/CFS to the perception of effort, and the medical approach (Maes and Twisk, BMC Med, 2010,8,35). The aim of this paper is to review how to construct a nomothetic model of ME/CFS using Partial Least Squares (PLS) path analysis and ensembling causome (bacterial translocation as assessed with IgM/IgA responses to LPS), protectome (lowered coenzyme Q10), adverse outcome pathways (AOP) including increased lysozyme, CD38+ T cell activation, cell-mediated immune activation (CMI), and IgM responses to oxidative specific epitopes and NO-adducts (IgM OSENO). Using PLS, we trained, tested and validated this knowledge- and data-driven causal ME/CFS model, which showed adequate convergence, construct and replicability validity. This bottom-up explicit data model of ME/CFS objectivates the descriptive narratives of the ME/CFS phenome, using causome-protectome-AOP data, whereby the abstract concept ME/CFS is translated into pathways, thereby securing the reification of the ME/CFS phenome. We found that 31.6% of the variance in the physiosomatic symptom dimension of ME/CFS was explained by the cumulative effects of CMI and CD38+ activation, IgM OSENO, IgA LPS, lysozyme (all positive) and coenzyme Q10 (inversely). Cluster analysis performed on the PLS-generated latent vector scores of all feature sets exposed three distinct immune groups of ME/CFS, namely one with increased lysozyme, one with increased CMI + CD38 activation + depressive symptoms, and another with increased bacterial translocation + autoimmune responses to OSENO.
BRIEF REPORT | doi:10.20944/preprints202010.0039.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: peritoneal catheter; PleurX, liver cirrhosis, refractory ascites, spontaneous bacterial peritonitis,
Online: 2 October 2020 (10:39:07 CEST)
Background and objectives: Refractory ascites markedly worsens prognosis in cirrhosis. Large volume paracentesis (LVP) is standard treatment, but complications are common. In a randomized controlled case-series, we assessed a permanent tunneled peritoneal catheter versus LVP in patients with cirrhosis and ascites. Materials and Methods: Random allocation was computer-generated, and concealment used opaque envelopes. Patients were included from 01-2017 to 12-2018. Inclusion criteria were cirrhosis and recurrent ascites and expected survival of more than 3 months. Results: Thirteen patients were enrolled (PleurX =6 versus LVP =7). Seven were female, age range 51 to 80 years. No procedure-related complications occurred. Two patients died due to variceal bleeding (PleurX-group) and sepsis (LVP-group). One patient was withdrawn due to hyponatremia (PleurX-group). Two patients were withdrawn due to bacterial peritonitis and infection of unknown origin (Control-group). In the PleurX-group, all patients colonized the catheter, two developed bacterial peritonitis. The most common bacterial colonization was Staph. Epidermidis (n=4). Conclusions: In selected patients, the PleurX catheter mobilizes ascites and may be an alternative to LVP. The risk of infection should be considered in each case. The impact of colonization and risk of infections needs further investigation. Trial Registration: EudraCT: CIV-16-10-017324; clinicaltrials.gov: NCT 03027635; Scientific Ethics Committee journal no: H-1604179
ARTICLE | doi:10.20944/preprints201912.0286.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Moringa oleifera; bismuth nanoparticles; polyphenolics; anti-bacterial; anti-fungal; antioxidant
Online: 21 December 2019 (12:28:21 CET)
The use of plant extracts in the synthesis of metal nanoparticles is a very attractive approach in the field of green synthesis. To benefit from the potential synergy between the biological activities of the Moringa oleifera leaves extract and metallic bismuth, our study aimed at synthesizing bismuth nanoparticles using a hydroalcoholic extract of M. oleifera leaves as a means of green synthesis that yields nontoxic products and reduces the production of wasteful material. To this end, the M. oleifera leaves extract was treated with a bismuth nitrate pentahydrate solution. A color change from light brown to dark brown indicates the synthesis of bismuth nanoparticles. The total phenolic content in the M. oleifera leaves extract used was 23.0 ± 0.3 mg gallic acid equivalent/g of dried M. oleifera leaves powder. Antioxidant property of MO synthesised bismuth Nanoparticles was evaluated and in line with the extract used in the synthesis of NPs. The physical properties of the synthesized bismuth nanoparticles were characterized using UV-Vis spectrophotometer, FT-IR spectrometer, TEM, SEM, and XRD. The synthesized bismuth nanoparticles have a size in the range of 40.4-57.8 nm with amorphous morphology. Using DPPH and phosphomolybdate assays, our findings revealed that the M. oleifera leaves extract and the synthesized bismuth nanoparticles possess antioxidant properties. Using resazurin microtiter assay, we also demonstrate that the M. oleifera leaves extract and the synthesized bismuth nanoparticles exert potent anti-bacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Enterococcus faecalis, similarly to the inhibition exerted by Moringa extract, especially against Enterococcus faecalis (MIC values for the extract: 500, 250, 250, and 250 µg/mL; MIC values for the bismuth nanoparticles: 500, 500, 500, and 250 µg/mL, respectively). Similarly, the M. oleifera leaves extract and the synthesized bismuth nanoparticles display relatively stronger anti-fungal activity against Aspergillus niger, Aspergillus flavus, Candida albicans, and Candida glabrata (MIC values for the extract: 62.5, 62.5, 125, and 250 µg/mL; MIC values for the bismuth nanoparticles: 250, 250, 62.5, and 62.5 µg/mL, respectively). Thus, the hydroalcoholic extract of M. oleifera leaves was successfully used in the synthesis of bismuth nanoparticles, showing a positive antioxidant, anti-bacterial, and anti-fungal activity. Therefore, the synthesized bismuth nanoparticles can potentially be employed in the alleviation of symptoms associated with oxidative stress and in the topic treatment of Candida infections.
ARTICLE | doi:10.20944/preprints201911.0305.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Moringa oleifera; copper nanoparticles; polyphenolics; anti-bacterial; anti-fungal; antioxidant
Online: 26 November 2019 (03:45:52 CET)
The synthesis of metal nanoparticles using plant extracts is a very promising method in green synthesis. The medicinal value of Moringa oleifera leaves and the anti-microbial activity of metallic copper were combined in the present study to synthesize copper nanoparticles having a desirable added-value inorganic material. The use of a hydroalcoholic extract of M. oleifera leaves for the green synthesis of copper nanoparticles is an attractive method as it leads to the production of harmless chemicals and reduces waste. The total phenolic content in the M. oleifera leaves extract was 23.0 ± 0.3 mg gallic acid equivalent/g of dried M. oleifera leaves powder. The M. oleifera leaves extract was treated with a copper sulphate solution. A color change from brown to black indicates the formation of copper nanoparticles. Characterization of the synthesized copper nanoparticles was performed using UV-Vis spectrophotometer, FT-IR spectrometer, TEM, SEM, and XRD. The synthesized copper nanoparticles have an amorphous nature and particle size of 35.8-49.2 nm. We demonstrate that the M. oleifera leaves extract and the synthesized copper nanoparticles display considerable antioxidant activity. Moreover, the M. oleifera leaves extract and the synthesized copper nanoparticles exert potent anti-bacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis (MIC values for the extract: 500, 250, 250, and 250 μg/mL; MIC values for the cooper nanoparticles: 500, 500, 500, and 250 μg/mL, respectively). Similarly, the M. oleifera leaves extract and the synthesized copper nanoparticles exert relatively more potent anti-fungal activity against Aspergillus niger, Aspergillus flavus, Candida albicans, and Candida glabrata (MIC values for the extract: 62.5, 62.5, 125, and 250 μg/mL; MIC values for the cooper nanoparticles: 125, 125, 62.5, and 31.2 μg/mL, respectively). Our study reveals that the green synthesis of copper nanoparticles using a hydroalcoholic extract of M. oleifera leaves was successful. In addition, the synthesized copper nanoparticles can be potentially employed in the treatment of various microbial infections due to their potent antioxidant, anti-bacterial, and anti-fungal activities.
ARTICLE | doi:10.20944/preprints201810.0113.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: Sea Squirts; Metabolites; GC-MS; Anti-bacterial; Zika vector; larvicidal
Online: 6 October 2018 (11:18:31 CEST)
In this present study, we conducted untargeted metabolic profiling using Gas Chromatography-Mass Spectrometry (GC-MS) analysis of ascidian Didemnum bistratum to assess the chemical constituents by searching in NIST library with promising biological properties against anti-bacterial and Zika virus vector mosquitocidal Properties. Metabolites, steroids and fatty acids are abundant in crude compounds of ascidian D. bistratum and showed potential zone growth inhibition against bacterial strains Kluyvera ascorbate (10 mm). The active crude compounds of D. bistratum exhibited prominent larvicidal activity against the Zika vector mosquitoes of Aedes aegypti and Cluex quinquefasciatus (LC50 values of 0.4436 to 2.23 mg/mL). The findings of this study provide a first evidence of the biological properties exhibited by D. bistratum extracts, thus increasing the knowledge about the Zika virus vector mosquitocidal properties of ascidian. Overall, ascidian D. bistratum are promising and biocontrol or eco-friendly tool against A. aegypti and C. quinquefasciatus with prospective toxicity against non-target organisms.
REVIEW | doi:10.20944/preprints201807.0091.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: bacterial infection; antibiotic resistance; bacteriophage; antibiotic therapy; phage therapy; review
Online: 5 July 2018 (10:09:09 CEST)
Bacteriophages, viruses that are widespread throughout the world, are highly specific for bacteria, usually of a single species and often of a particular strain. After being discovered and isolated 100 years ago, their use, called phage therapy, was instituted in medicine two years later and quickly used around the world to treat various bacterial infections. In the West, phage therapy was overshadowed in the second half of the 20th century by antibiotic therapy, which was then thought to be the definitive solution. But because of the increase in bacterial resistance to antibiotics, the idea of using bacteriophages in medicine has been reawakened. The innumerable observations reported over the years in the literature constitute an invaluable experience. We and some of our colleagues have, in the last decade treated some patients compassionately. With the available documentation and our own experience we discuss the potential indications and limitations of phage therapy. The observation of the increasing number of therapeutic failures in the announced perspective of a post-antibiotic era, we believe, that the introduction of bacteriophages into the therapeutic arsenal seems conceivable today to two preconditions: that their production as biologic drug meets current regulatory standards and that the benefit-risk assessment was conducted in a modern setting. Phage therapy could be applied as a substitution or supplement to antibiotic therapy under multiple circumstances in different modes, precise indications and limits.
ARTICLE | doi:10.20944/preprints201804.0128.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: bacterial artificial chromosomes; RNAseq; genetic map; transposable element; gene density
Online: 10 April 2018 (10:49:41 CEST)
Many dioecious plants have sex chromosomes that are cytologically heteromorphic, but about half of species lack cytological differences between males and females and are thus homomorphic. Very little is known about the size and content of the non-recombining sex-determining region (SDR) in these species. Here, we assess the size and content of the SDR of the diploid dioecious herb Mercurialis annua, which has homomorphic sex chromosomes and shows signatures of mild Y-chromosome degeneration. We used RNAseq to identify new Y-linked markers for M. annua. Twelve of 24 transcripts with male-specific and male-biased expression could only be PCR-amplified from males and are thus Y-linked. We found a further six Y-linked sequences that were present in males but not females using genome capture data from multiple populations. We used the Y-linked sequences to identify and sequence 17 sex-linked bacterial artificial chromosomes (BACs), which form 11 groups of non-overlapping sequence, covering a total sequence length of about 1.5 Mb. Content analysis of this region suggests it is enriched for repeats, has a low gene density and contains few candidate sex-determining genes. The BACs map to a subset of the sex-linked region of the genetic map, which is estimated to be at least 14.5 Mb. This is substantially larger than estimates for other dioecious plants with homomorphic sex chromosomes, especially given the small genome size of M. annua. Our data provide a rare, high-resolution view of the homomorphic Y chromosome of a dioecious plant.
ARTICLE | doi:10.20944/preprints202309.2052.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: Bacterial resistance; Metal nanoparticles; Rhododendron arboreum; S. aureus; Cell membrane; Photocatalysis
Online: 29 September 2023 (04:12:41 CEST)
It is important to develop new antibacterial drugs since the emergence of bacterial resistance to available antibiotics. Metal nanoparticles have the potential to combat antibiotic resistance and are effective antibacterial agents. Here, we demonstrate the biogenic production of zinc nanoparticles using Rhododendron arboreum stem bark. The biosynthesized ZnNPs were characterized through different analytical techniques such as UV-vis, FTIR, EDX, SEM, and XRD. Clinical isolates such as E. coli, S. aureus, and K. pneumonia were used to check the antibacterial efficacy of the biosynthesized zinc nanoparticles. The MIC and MBC values against K. pneumonia, S. aureu, and E. coli were found to be 34±0.21 and 11.71±0.47, 47±0.11 and 23.86±0.84 and 94±0.18 and 40.43±0.16 µg/mL, respectively. It dramatically decreased the integrity of the cell membrane and markedly increased the permeability of both inner and outer membranes. The green synthesized ZnNPs have good catalytic activity. It degraded 65% of methyl orange dye within 6h when the mixture was kept in direct sunlight, thus demonstrating good photodegradation potential and can be employed as a good photocatalyst. According to these results, biosynthesized zinc nanoparticles could be a potential therapy option for controlling bacterial pathogenesis and an effective photocatalyst for the elimination of hazardous water contaminants.
ARTICLE | doi:10.20944/preprints202305.1747.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Gram +; Gram -; Thymus vulgaris L. essential oil; contact time; bacterial growth
Online: 25 May 2023 (07:10:47 CEST)
Overuse and misuse of antibiotics can pose the risks of spreading mutant strains that show antimicrobial resistance (AMR), with negative impact on management of bacterial infections and economic implications on healthcare systems. Research and development of natural antibacterial agents could be a priority in the next years to improve number of effective antibacterial molecules and to reduce AMR phenomenon and its development. The present study identified the most effective concentration and contact time of Thymus vulgaris L. essential oil (TEO) to obtain bactericidal effect in vitro against different Gram + and Gram – bacterial strains. Six clinically isolated (wild types) bacterial strains, (Citrobacter freundii, Enterococcus feciorum, Proteus mirabilis, Acinetobacter cioffi, Pasteurella putrefaciens, Klebsiella pneumoniae) and two ATCC (Staphylococcus aureus and Streptococcus mutans) were tested after 1min, 3min and 5min of contact with TEO. Preliminary results on S. aureus after 24h incubation revealed a TEO concentration of 9.28mg/mL (w/v) that completely inhibited bacteria growth keeping cell viability. Total suppression of bacterial growth at all tested contact times was observed for all tested bacterial strains and the results were confirmed after 48h incubation. Bacterial growth suppression was confirmed even with presence of organic component. These preliminary results showed in vitro antimicrobial efficacy of TEO against different Gram+ and Gram- bacterial strains. Future studies are necessary to confirm the reproducibility of these results even on other strains and to define exactly the molecular mechanisms of EOs, in order to consider TEO as a valid alternative of classic antibiotic therapies and subsequently to reduce the occurrence of AMR.
ARTICLE | doi:10.20944/preprints202304.1136.v1
Subject: Environmental And Earth Sciences, Ecology Keywords: Bacterial communities; Fungal communities; Mineral-solubilizing microbial inoculums; Robinia pseudoacacia L.
Online: 28 April 2023 (07:29:24 CEST)
The addition of mineral-solubilizing microbial inoculums is a kind of biological measure for vegetation restoration of rock mining areas. Its function is to accelerate soil weathering, improve soil fertility, improve the ability of plants to fix soil. Through understanding the response of plant rhizosphere microbial community to the mineral-solubilizing microbial inoculums, it is helpful to popularize the use of mineral-solubilizing microbial inoculums. However, little is known about the changes of plant rhizosphere soil microbial communities after the addition of mineral-solubilizing microbial inoculums. Therefore, the purpose of this study was to reveal the pasthways through which different mineral-solubilizing microbial inoculums positively affect underground part of R. pseudoacacia. A pot experiment was conducted to investigate the responses of rhizosphere soil bacterial and fungal communities in R. pseudoacacia by taking 32 samples from four different mineral-solubilizing microbial inoculums treatments. The results showed that the effect of mineral-solubilizing microbial inoculums on the structure of fungal community was greater than that of bacterial community. But the relative abundance of Proteobacteria was increased, which had a strong positive correlation with root nodulation. In terms of microbial diversity, mineral-solubilizing microbial inoculums had a greater effect on the diversity and evenness of bacterial community. It is worth noting that correlation analysis showed that Proteobacteria and Verrucomicrobia in bacteria and Ascomycota and Zoopagomycota in fungi were positively correlated with soil enzyme activity and plant growth. RDA analysis showed that the relative abundance of these two phyla in bacteria also had positive effects on plant root nodulation. Our results showed that the addition of mineral-solubilizing microbial inoculums can optimize the rhizosphere soil microbial community structure, promote R. pseudoacacia root nodulation, and enhance the nitrogen fixation capacity of plants. In addition, this study can provide a theoretical basis for the application of mineral-solubilizing microbial inoculums to a wide range of slope ecological restoration.
ARTICLE | doi:10.20944/preprints202304.0946.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: acute appendicitis; bacterial culture; children; appendiceal lumen; peritoneal cavity; complicated appendicitis
Online: 26 April 2023 (03:41:39 CEST)
Background: Primary infection has been questioned as the pathogenetic cause of acute appendicitis. We attempted to identify the bacteria involved, and to investigate if their species, types, or combinations affected the severity of acute appendicitis in children. Methods: Samples from both the appendiceal lumen and the peritoneal cavity of 72 children who underwent appendectomy were collected to perform bacterial culture analysis. The outcomes were studied to see if and how they were associated with the severity of the disease. Regression analysis was performed to identify any risk factors associated with complicated appendicitis. Results: Escherichia coli, Pseudomonas aeruginosa and Streptococcus species were the most common pathogens found in the study population. The same microorganisms, either combined or separate, were the most common in the appendiceal lumen and the peritoneal cavity of patients with complicated appendicitis. Gram-negative bacteria, polymicrobial cultures in the peritoneal fluid and in the appendiceal lumen, were associated with complicated appendicitis. Polymicrobial cultures in the peritoneal cavity presented four times higher risk of complicated appendicitis. Conclusion: Polymicrobial presentation and gram-negative bacteria are associated with complicated appendicitis. Antibiotic regimens should target the combinations of the most frequently identified pathogens, speculating the value of early antipseudomonal intervention.
REVIEW | doi:10.20944/preprints202302.0391.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: small ORF encoded polypeptides (SEPs); riboproteogenomics; bacterial pathogens; protein tagging; proteomics
Online: 23 February 2023 (01:25:52 CET)
The ever-growing repertoire of genomic techniques continues to expand our understanding of true diversity and richness of prokaryotic genomes. Riboproteogenomics laid the foundation for dynamic studies of previously overlooked genomic elements. Most strikingly, bacterial genomes were revealed to harbour robust repertoires of small open reading frames (sORFs) encoding a diverse and broadly expressed range of small proteins, or sORF-encoded polypeptides (SEPs). In recent years, continuous efforts led to great improvements in annotation and characterization of such proteins, yet many challenges remain to fully understand the pervasive nature of small proteins and their impact on bacterial biology. In this work we review recent developments in the dynamic field of bacterial genome reannotation, catalogue important biological roles carried out by small proteins and identify challenges obstructing the way to full understanding of these elusive proteins.
ARTICLE | doi:10.20944/preprints202111.0158.v1
Subject: Biology And Life Sciences, Forestry Keywords: Cinnamomum camphora; chemotype; soil nutrient; soil bacterial community diversity and structure
Online: 8 November 2021 (15:20:35 CET)
Abstract: Plant types and soil bacterial communities had a close relationship, understanding the profound association between them contributes to better learn bacterial ecological function for plant growth. In this study, rhizosphere soil of six different chemotype Cinnamomum camphora trees were collected, including C. bodinieri var. citralifera, [C. camphora (Linn.) Presl], camphora-type, cineole-type, linalool-type and isoborneol-type. Soil properties content and bacterial communities were analyzed. Two chemotype C. camphora, including [C. camphora (Linn.) Presl] and linalool-type, shaped similar bacterial community structure, decreased Firmcutes relative abundance. richness estimators (Chao1 index and Ace index) of [C. camphora (Linn.) Presl] were decreased compared with the others. Furthermore, soil bacterial community structure was also similar among bodinieri var. citralifera, camphora-type, cineole-type and isoborneol-type. Hence, different chemotype C. camphora altered soil nutrient and shaped rhizosphere bacterial communities.
REVIEW | doi:10.20944/preprints202107.0182.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: CRISPR-Cas9; Genome editing; plant editing; bacterial immune system; genetic disease
Online: 8 July 2021 (09:50:22 CEST)
Clustered regularly interspaced short palindromic repeats or CRISPR, one of the major technological tools from nature's toolbox, has revolutionized the scientific world with its potential use in humans and plants. CRISPR Cas9 was first known as an adaptive immune system of bacteria. It is a system that cleaves foreign DNA. It has been exploited to be used as a genome editing tool for correcting genetic diseases in humans, for plants to create stress-resistant plants, and for a variety of different purposes. This review provides a basic overview of its applications in different areas of biological research. It has immense potential for a variety of researches, but it's still a mystery for science. It feels like scientists just know a tip of an iceberg.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: 16S rRNA gene; bacterial diversity; catabolic activity; cultivation; Pannonian steppe; pyrosequencing
Online: 22 June 2021 (14:26:55 CEST)
In this study, we examined the effect of salinity and alkalinity on the metabolic potential and taxonomic composition of microbiota inhabiting the sodic soils at different plant communities. The soil samples were collected in the Pannonian steppe (Hungary, Central Europe) under extreme dry and wet weather conditions. The metabolic profiles of microorganisms were analysed by MicroResp method, the bacterial diversity was assessed by cultivation and next generation amplicon sequencing based on the 16S rRNA gene. Catabolic profiles of microbial communities varied primarily according to the alkali vegetation types. Most members of the strain collection were identified as plant associated and halophilic/alkaliphilic species of Micrococcus, Nesterenkonia, Nocardiopsis, Streptomyces (Actinobacteria) and Bacillus, Paenibacillus (Firmicutes) genera. Based on the pyrosequencing data, the relative abundance of phyla Proteobacteria, Actinobacteria, Acidobacteria, Gemmatimonadetes and Bacteroidetes changed also mainly with the sample types, indicating distinctions within the compositions of bacterial communities according to the sodic soil alkalinity-salinity gradient. The effect of weather extremes was the most pronounced in the relative abundance of phyla Actinobacteria and Acidobacteria. The type of alkali vegetation caused greater shifts in both the diversity and activity of sodic soil microbial communities than the extreme aridity and moisture.
ARTICLE | doi:10.20944/preprints202106.0434.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: bacterial community composition; metabolic activity; microbial diversity; soil erosion; soil quality
Online: 16 June 2021 (10:23:06 CEST)
Among the agricultural practices promoted by the Common Agricultural Policy to increase soil functions, the use of cover crops is a recommended tool to improve the sustainability of Mediter-ranean woody crops such as olive orchards. However, there is a broad range of cover crop ty-pologies in relation to its implementation, control and species composition. In that sense, the in-fluence of different plant species on soil quality indicators in olive orchards remains unknown yet. This study describes the effects of four treatments based on the implementation of different ground covers (CC-NAT, CC-GRA and CC-MIX) and conventional tillage (TILL) on soil erosion, soil physicochemical and biological properties, and soil microbial communities after 8 years of cover crop establishment. Our results have demonstrated that the presence of a temporary cover crop (CC), compared to a soil under tillage (TILL), can reduce soil losses and maintain good soil physicochemical properties and modify greatly the structure and diversity of soil bacterial com-munities and its functioning. The presence of a homogeneous CC of gramineous (Lolium rigidum or Lolilum multiflorum) (CC-GR) for 8 years significantly increased the functional properties of the soil as compared to TILL; although the most significant change was a modification on the bacte-rial community composition that was clearly different from the rest of treatments. On the other hand, the use of a mixture of plant species (CC-MIX) as a CC for only two years although did not modify greatly the structure and diversity of soil bacterial communities compared to the TILL soil, induced significant changes on the functional properties of the soil, and reverted those properties to a level similar to that of an undisturbed soil that had maintained a natural cover of spontaneous vegetation for decades (CC-NAT).
ARTICLE | doi:10.20944/preprints202007.0162.v1
Subject: Engineering, Chemical Engineering Keywords: Heterotrophic denitrification; Granular activated carbon (GAC); Bacterial Community; 3D-BER system
Online: 9 July 2020 (01:51:11 CEST)
In this study, a three-dimensional bioelectrochemical reactor system (3D-BERs) with granular activated carbon (GAC) epitomizes a novel treatment technology for treating nitrate-polluted water. The conventional denitrification process faces many challenges, including the huge demand for organic carbon, long-term accumulation of intermediate products, and the adaptation period. Results shown that under the optimal conditions of the COD/NO3--N ratio was 1.5, the denitrification efficiency reached 98.62%, when compared to 81.12% at COD/ NO3--N ratio of 3.5, and the initial pH of 7.5 ± 0.5, NO3--N was entirely removed at 2.2 h without accumulation of nitrite. The high initial ratio of NO2--N/NO3--N is mainly to accelerate the denitrification rate by accelerating the reduction of nitrite. Denitrification process followed by zero-order kinetics linear model for at different concentrations of inlet NO3--N, and achieved higher denitrification rate at greater inlet NO3--N concentration. High-throughput sequencing shows that the community structure and relative abundance of bacteria changed significantly, especially at the genes and the phyla level in immobilized GAC particles. Microbial composition enhanced the removal of nitrogen at the inner surface (IS) and bottom surface (BS) of immobilized GAC carriers. Therefore, this system is expected to be a more efficient and useful supplement or a cost-effective alternative compared to the traditional low carbon to nitrogen wastewater treatment system.
ARTICLE | doi:10.20944/preprints201912.0373.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: bacterial flagellar motility; flagellin; Salmonella; FljB; FliC; electron cryomicroscopy; viscosity; infection
Online: 29 December 2019 (07:47:57 CET)
The bacterial flagellum is a motility organelle, consisting of a long helical filament as a propeller and a rotary motor that drives rapid filament rotation to produce thrust. Salmonella enterica serovar Typhimurium has two genes of flagellin, fljB and fliC, for flagellar filament formation and autonomously switches their expression at a frequency of 10-3–10-4 per cell per generation. We report here differences in their structures and motility functions under high viscosity conditions. A Salmonella strain expressing FljB showed a higher motility than the one expressing FliC under high viscousity. To examine the reasons for this motility difference, we carried out structural analyses of the FljB filament by electron cryomicroscopy and found that the structure is nearly identical to that of the FliC filament except for the position and orientation of the outermost domain D3 of flagellin. The density of domain D3 was much lower in FljB than FliC, suggesting that domain D3 of FljB is more flexible and mobile than that of FliC. These differences suggest that domain D3 plays an important role not only in changing antigenicity of the filament but also in optimizing motility function of the filament as a propeller under different conditions.
ARTICLE | doi:10.20944/preprints202309.1869.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Enterocins; Enterococcus; breast-fed infants; bacterial infection; Listeria monocytogenes; selective inhibition; probiotic
Online: 27 September 2023 (09:17:31 CEST)
Enterocins are bacteriocins synthesized by Enterococcus strains that show an interesting antimi-crobial effectiveness against foodborne pathogens such as Listeria monocytogenes. The objectives of this study were identify and analyze the expression of enterocin genes of Enterococcus isolated from breast-fed infants and evaluate the ability to inhibit three human isolates of virulent Lis-teria monocytogenes, as well as some probiotic bacteria. The susceptibility of the strains of L. mon-ocytogenes to fifteen antibiotics was tested, detecting resistance to cefoxitin (constitutive-ly resistant), oxacillin and clindamycin. Production of enterocins A, B and P were observed in Enterococcus faecium isolates, and enterocin AS-48 in an Enterococcus faecalis isolate. AS-48 showed antilisterial activity by itself, while the joint action of enterocins A and B, or B and P was neces-sary for inhibiting L. monocytogenes, demonstrating a synergistic effect of those combinations. The presence of multiple enterocin genes does not assured the inhibition of L. monocytogenes strains. However, the expression of multiple enterocin genes showed a good correlation with the inhibition capacity of these strains. Furthermore the potential beneficial strains of lactobacil-li and bifidobacteria examined were not inhibited by any of the enterocins produced individu-ally or in combination, with the exception of Bifidobacterium longum BB536, which was inhibited by enterocin AS-48 and the joint production of enterocins A and B or B and P. The enterocins studied here could be candidates for developing alternative treatments against antibi-otic-resistant bacterial infections. Moreover, these selected enterocin-producing E. faecium strains isolated from breast-fed infants could be used as probiotic strains due to their antilisterial effect as well as the absence of virulence factors.
BRIEF REPORT | doi:10.20944/preprints202305.1931.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: 16S rRNA gene; phylogenetics; amplicon metagenomics; bacterial species; gene structure and sequence
Online: 26 May 2023 (11:38:01 CEST)
Bacterial phylogenetics has largely been determined via 16S rRNA gene sequencing and phylogenetic tree reconstruction. Observed utility of this approach has driven the popularity of the 16S rRNA gene amplicon metagenomics method for profiling and identifying diverse microbes from specific habitats. This work sought to develop universal primers for amplifying the 16S rRNA gene from a consortium of disparate microbial species. Using multiple sequence alignment of the 16S rRNA gene of a variety of microbes, the resulting highly conserved region of the consensus sequence was used for design of universal polymerase chain reaction (PCR) primers for 16S rRNA gene. Application of the universal primers in simulated PCR reveals poor amplification efficiency where only 12 species out of 31 generated an amplicon. BLAST analysis of the resulting amplicons reveals a classification error of 50%. More significantly, analysis of the amplicon length indicates variable read length ranging from 81 to 122 base pair compared to the predicted read length of 100 base pairs. This suggests that the 16S rRNA gene harbours significant hitherto underappreciated sequence diversity, and may have unknown alternative splicing and recombination mechanisms. Overall, results from this study suggests that primer design for 16S rRNA amplicon metagenomics may be application and habitat specific, where it is difficult to design universal primers for all bacterial species. Conceptually, this meant that there may be sequence co-evolution in 16S rRNA gene for microbial species in the habitat where environmental and nutritional conditions impact on 16S rRNA gene structure and sequence. In essence, 16S rRNA gene may habour epigenetics signals at the gene level.
REVIEW | doi:10.20944/preprints202304.1082.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: bacterial spores; spore display system technology; mucosal vaccine; spore engineering; Bacillus subtilis
Online: 27 April 2023 (15:31:29 CEST)
Mucosal vaccines offer several advantages over injectable conventional vaccines, such as adaptive immunity induction, secretory IgA production at the entry site of most pathogens, and needleless vaccinations. Despite their potential, only a few mucosal vaccines are currently used. Developing new effective mucosal vaccines strongly relies on identifying innovative anti-gens, efficient adjuvants, and delivery systems. Several approaches based on phages, bacteria, or nanoparticles have been proposed to deliver antigens to mucosal surfaces. Bacterial spores have also been considered antigen vehicles, and various antigens have been successfully exposed on their surface. Due to their peculiar structure, the spores conjugate the advantages of live microorganisms with synthetic nanoparticles. When mucosally administered, spores expressing anti-gens have been shown to induce antigen-specific, protective immune responses. This review accounts for recent progress in the formulation of spore-based mucosal vaccines, describing the spore's structure, specifically the spore surface, and the diverse approaches developed to improve its efficiency as a vehicle for heterologous antigen presentation.
ARTICLE | doi:10.20944/preprints202304.0337.v1
Subject: Biology And Life Sciences, Forestry Keywords: wooden buildings; national treasures; termite damage; bacterial entomopathogenic; cuticle disintegration; termiticidal effect
Online: 14 April 2023 (03:17:20 CEST)
Biocontrol strategies are gaining tremendous attention with the growing awareness of the irreparable harm caused by the continuous use of synthetic pesticides. This study examines the proteolytic and chitinolytic activities of Bacillus velezensis CE 100 and its termiticidal effect through cuticle degradation. The proteolytic and chitinolytic activities of B. velezensis CE 100 systematically increased with cell growth to the respective peak of 68.3, and 128.3 units/mL after seventh days of inoculation, corresponding with the highest cell growth of 16 x 107 colony forming units (CFU)/mL. The in vitro termiticidal assay showed that B. velezensis CE 100 caused a rapid and high rate of termite mortality with the median lethal time (LT50) of > 1h, and the highest mortality rate of 91.1% and 92.2% recorded at 11h and 12h in the bacterial broth culture and crude enzyme fraction, respectively. In addition to broken setae and deformed sockets, termites treated with the bacterial broth culture exhibited degraded epicuticles, while the crude enzyme fraction caused severe disintegration of both the epicuticle and endocuticle. These results indicate a tremendously higher prospect of B. velezensis CE 100 in the biological control of subterranean termites compared to the previously used entomopathogenic bacteria.
ARTICLE | doi:10.20944/preprints202211.0375.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Cr stress; rhizosphere bacterial community; Iris tectorum; 16S rRNA sequencing technology; Phytoremediation
Online: 21 November 2022 (06:27:02 CET)
With the rapid development of industry, Cr has become one of the major heavy metal pollutants in soil, which has caused serious effects on the soil's ecological environment. However, the effects of Cr stress on bacterial communities in plant rhizosphere soils remain unclear. In this study, I. tectorum was selected as the research object, and 16S rRNA high-throughput sequencing technology was used to analyze the effects of Cr stress on the structure and diversity of the bacterial community in the rhizosphere soil of I. tectorum. The results showed that I. tectorum had strong tolerance and enrichment to Cr. However, under Cr stress, the diversity and abundance index of rhizosphere bacteria decreased by 8.5% and 6.8% on average, and the Sobs index decreased by 7.6%. Moreover, the bacterial community changed by 20.1% due to the addition of Cr, further leading to a 15.9% decrease in the common species of the bacterial community, among which Proteobacteria, Actinobacteria, Chloroflexi and Acidobacteriota accounted for more than 74.8% of the total sequence. According to the symbiosis network diagram, it was found that under a two-cultivated pattern, the synergizing effect between dominant bacteria was significantly enhanced, and the soil microenvironment was improved. Redundancy analysis showed that C, N, and P nutrient elements and Cr contents in uncontaminated and contaminated soils were the primary driving factors for the succession of I. tectorum rhizosphere bacterial community, and the response was stronger after Cr(Ⅵ) was added. In conclusion, the results of this study will provide insights into the response of rhizosphere bacterial communities to heavy metal Cr and the interactions between wetland plants and rhizosphere bacteria in wetland phytoremediation.Keywords: Cr stress; rhizosphere bacterial community; Iris tectorum; 16S rRNA sequencing technology; Phytoremediation
ARTICLE | doi:10.20944/preprints202112.0049.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: bacterial wilt; biological control; phage; microscopy; sequencing; molecular characterization; genomic characterization; depolymerase
Online: 3 December 2021 (10:36:47 CET)
Ralstonia solanacearum is the causative agent of bacterial wilt, one of the most destructive plant diseases. While chemical control has an environmental impact, biological control strategies can allow sustainable agrosystems. Three lytic bacteriophages (phages) of R. solanacearum with biocontrol capacity in environmental water and plant were isolated from river water in Europe but not fully characterized, their genomic characterization being fundamental to understand their biology. In this work, the phage genomes were sequenced and subjected to bioinformatic analysis. The morphology was also observed by electron microscopy. Phylogenetic analyses were performed with a selection of phages able to infect R. solanacearum and the closely related phytopathogenic species R. pseudosolanacearum. The results indicated that the genomes of vRsoP-WF2, vRsoP-WM2 and vRsoP-WR2 range from 40,688 to 41,158 bp with almost 59% GC-contents, 52 ORFs in vRsoP-WF2 and vRsoP-WM2, and 53 in vRsoP-WR2 but, with only 22 or 23 predicted proteins with functional homologs in databases. Among them, two lysins and one exopolysaccharide (EPS) depolymerase, this type of depolymerase being identified in R. solanacearum phages for the first time. These three European phages belong to the same novel species within the Gyeongsanvirus, Autographiviridae family (formerly Podoviridae). These genomic data will contribute to a better understanding of the abilities of these phages to damage host cells and, consequently, to an improvement in the biological control of R. solanacearum.
REVIEW | doi:10.20944/preprints202108.0383.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Bacterial carotenoids; Cell disruption; HPLC separation; MS analysis; Food and textile applications
Online: 18 August 2021 (14:09:35 CEST)
Natural carotenoids are secondary metabolites that exhibit antioxidant, anti-inflammatory and anti-cancer properties. These types of compounds are in high demand by pharmaceutical, cosmetic, textile and food industries, leading to the search for new natural sources of carotenoids. In recent years, the production of carotenoids from bacteria has become of great interest for industrial applications. In addition to carotenoids with C40-skeletons, some bacteria have the ability to synthesize characteristic carotenoids with C30-skeletons. In this regard, a great variety of methodologies for the extraction and identification of bacterial carotenoids has been reported and this is the first review that condenses much of this information. To understand the diversity of these carotenoids, we present their biosynthetic origin in order to focus on the methodologies employed in their extraction and characterization. Special emphasis has been made on high-performance liquid chromatography-mass spectrometry (HPLC-MS) for the analysis and identification of bacterial carotenoids. We end up this review showing their potential commercial use of bacterial carotenoids. This review is proposed as a guide for the identification of these metabolites, which are frequently reported in new bacteria strains.
ARTICLE | doi:10.20944/preprints202105.0182.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: chronic fatigue syndrome; Myalgic encephalomyelitis; oxidative stress; neuro-immune; inflammation; bacterial translocation
Online: 10 May 2021 (12:27:45 CEST)
Background: A meaningful part of schizophrenia patients suffer from physiosomatic symptoms (formerly named psychosomatic) which are reminiscent of chronic fatigue syndrome and fibromyalgia (FF) and are associated with signs of immune activation and increased levels of tryptophan catabolites (TRYCATs). Aims: To examine whether FF symptoms in schizophrenia are associated with breakdown of the paracellular pathway, zonulin, lowered natural IgM responses to oxidative specific epitopes (OSEs); and whether FF symptoms belong to the behavioral-cognitive-physical-psychosocial-(BCPS)-worsening index consisting of indices of a general cognitive decline (G-CoDe), symptomatome of schizophrenia, and quality of life (QoL)-phenomenome. Methods: FF symptoms were assessed using the Fibromyalgia and Chronic Fatigue Rating scale in 80 schizophrenia patients and 40 healthy controls and serum cytokines/chemokines, IgA levels to TRYCATs, IgM to OSEs, zonulin and transcellular/paracellular (TRANS/PARA) molecules were assayed using ELISA methods. Results: A large part (42.3%) of the variance in the total FF score was explained by the regression on the PARA/TRANS ratio, pro-inflammatory cytokines, IgM to zonulin, IgA to TRYCATs (all positively) and IgM to OSEs (inversely). There were highly significant correlations between the total FF score and G-CoDe, symtopmatome, QoL phenomenome and BCPS-worsening score. FF symptoms belong to a common core shared by G-CoDe, symtopmatome, and QoL phenomenome. Discussion: The physio-somatic symptoms of schizophrenia are driven by various pathways including increased zonulin, breakdown of the paracellular tight-junctions pathway, immune activation with induction of the TRYCAT pathway, and consequent neurotoxicity. It is concluded that FF symptoms are part of the phenome of schizophrenia and BCPS-worsening as well.
ARTICLE | doi:10.20944/preprints202101.0437.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Candida albicans biofilm; Mixed salivary bacterial biofilm; Phosphated PMMA; Antimicrobials; Salivary pellicle
Online: 22 January 2021 (09:34:24 CET)
Biofilms play a crucial role in the development of Candida-associated denture stomatitis. Inhibition of microbial adhesion to PMMA and phosphate containing PMMA has been examined in this work. C. albicans and mixed salivary microbial biofilms were compared on naked and salivary pre-conditioned PMMA surfaces in the presence or absence of antimicrobials (cetyl pyridinium chloride [CPC], KSL-W, histatin 5 [his 5]). Polymers with varying amounts of phosphate (0-25%) were tested using four C. albicans oral isolates as well as mixed salivary bacteria and 24 h biofilms were assessed for metabolic activity and confirmed using Live/Dead staining and confocal microscopy. Biofilm metabolism was reduced as phosphate density increased (15%: P=0.004; 25%: P=0.001). Loading of CPC on 15% phosphated disks showed a substantial decrease (P=0.001) in biofilm metabolism in the presence or absence of a salivary pellicle. Salivary pellicle on uncharged PMMA enhanced the antimicrobial activity of CPC only. CPC also demonstrated remarkable antimicrobial activity on mixed salivary bacterial biofilms under different conditions displaying the potent efficacy of CPC (350 µg/ml) when combined with an artificial protein pellicle (Biotene half strength).
ARTICLE | doi:10.20944/preprints202010.0441.v2
Subject: Engineering, Automotive Engineering Keywords: coronavirus; wastewater treatment techniques; mathematical model; statistical procedures; bacterial reactors, anaerobic ponds
Online: 8 January 2021 (13:22:36 CET)
This paper presents multidisciplinary and innovative research concerning fighting against coronavirus through wastewater collection and treatment. Studies suggest that coronavirus exists in the wastewaters. Untreated wastewater is proved to spread the virus. Coronavirus is attacking people globally and shrinking the economy. This paper highlights the idea that the coronavirus shall be defeated with the help of wastewater collection and treatment as well. The question addressed by this paper is will communities defeat the coronavirus without well-collected and treated wastewaters? This research aims to display the role of wastewaters in the spread of coronavirus in cities and to require their collection. The methods to achieve the goals are theoretical surveys, case study strategy, mathematical modeling, statistical procedures, forecasting of future, and dialectical discussions. The findings of this research demonstrate the need for carefully collected and treated wastewaters to overcome the coronavirus. This paper gives suitable techniques to collect and treat wastewater such as wastewater stabilization ponds, bacterial reactors, and anaerobic ponds. The innovative idea of this paper, its suggested indicators to select a certain wastewater treatment technique in every city, and its outcome will assist the global community to fight the coronavirus more effectively.
ARTICLE | doi:10.20944/preprints202012.0116.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: antibacterial coating; antimicrobial peptide; plasma polymer; LL 37; Magainin; Parasin; bacterial attachment
Online: 4 December 2020 (14:56:18 CET)
To combat infections on biomedical devices, antimicrobial coatings have attracted considerable attention, including coatings comprising naturally occurring antimicrobial peptides (AMPs). In this study the aim was to explore performance upon extended challenge by bacteria growing in media above samples. The AMPs LL37, Magainin 2, and Parasin 1 were covalently grafted onto a plasma polymer platform, which enables application of this multilayer coating strategy to a wide range of biomaterials. Detailed surface analyses were performed to verify the intended outcomes of the coating sequence. Samples were challenged by incubation in bacterial growth media for 5 and 20 hrs. Compared with the control plasma polymer surface, all three grafted AMP coatings showed considerable reductions in bacterial colonization even at the high bacterial challenge of initial seeding at 1x107 CFU, but there were increasing numbers of dead bacteria attached to the surface. All three grafted AMP coatings were found to be non-toxic to primary fibroblasts. These coatings thus could be useful to produce antibacterial surface coatings for biomaterials, though possible consequences arising from the presence of dead bacteria need to be studied further, and compared to non-fouling coatings that avoid attached dead bacteria.
ARTICLE | doi:10.20944/preprints202008.0677.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Nasal microbiota; Illumina sequencing; nanopore sequencing; 16S rRNA gene; Bacterial species; Corynebacterium
Online: 30 August 2020 (16:04:50 CEST)
Illumina and nanopore sequencing technologies are powerful tools that can be used to determine the bacterial composition of complex microbial communities. In this study, we compared nasal microbiota results at genus level using both Illumina and nanopore 16S rRNA gene sequencing. We also monitored the progression of nanopore sequencing in the accurate identification of species, using pure, single species cultures, and evaluated the performance of the nanopore EPI2ME 16S data analysis pipeline. Fifty-nine nasal swabs were sequenced using Illumina MiSeq and Oxford Nanopore 16S rRNA gene sequencing technologies. In addition, five pure cultures of relevant bacterial species were sequenced with the nanopore sequencing technology. The Illumina MiSeq sequence data were processed using bioinformatics modules present in the Mothur software package. Albacore and Guppy base calling, a workflow in nanopore EPI2ME and an in house developed bioinformatics script were used to analyze the nanopore data. At genus level, similar bacterial diversity profiles were found, and five main and established genera were identified by both platforms. However, probably due to mismatching of the nanopore sequence primers, the nanopore sequencing platform identified Corynebacterium in much lower abundance compared to Illumina sequencing. Further, when using default settings in the EPI2ME workflow, almost all sequence reads that seem to belong to the bacterial genus Dolosigranulum and a considerable part to the genus Haemophilus were only identified at family level. Nanopore sequencing of single species cultures demonstrated at least 88% accurate identification of the species at genus and species level for 4/5 strains tested, including improvements in accurate sequence read identification when the basecaller Guppy and Albacore, and when flowcell versions R9.4 and R9.2 were compared.
ARTICLE | doi:10.20944/preprints201808.0214.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: immunomagnetic separation (IMS); bacterial pathogen; 3D printing; preconcentration; DNA purification; molecular diagnostics
Online: 12 August 2018 (19:26:04 CEST)
Molecular detection of pathogens in clinical samples often requires pretreatment techniques, including immunomagnetic separation and magnetic silica bead (MSB)-based DNA purification to obtain the purified DNA of pathogens. These two techniques usually rely on handling small tubes containing a few millilitres of the sample and manual operation, implying that an automated system encompassing both techniques is needed for larger quantities of the samples. Here, we report a 3D-printed microfluidic platform that enables bacterial preconcentration and genomic DNA (gDNA) purification for improving the molecular detection of target pathogens in blood samples. The device consists of two microchannels and one chamber, which can be used to preconcentrate pathogens bound to antibody-conjugated magnetic nanoparticles (Ab-MNPs) and subsequently extract gDNA using magnetic silica beads (MSBs) in a sequential manner. The device was able to preconcentrate very low concentrations of pathogens and extract their genomic DNA in 10 mL of 10% blood within 30 min, and thus allowed polymerase chain reaction (PCR) and quantitative PCR to detect 1 colony forming unit of Escherichia coli O157:H7 in 10% blood. The results suggest that the 3D-printed microfluidic platform is highly useful for lowering the limitations on molecular detection in blood by preconcentrating the target pathogen and isolating its DNA in a large volume of the sample.
ARTICLE | doi:10.20944/preprints201805.0356.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Scoprion Venoms; Hos Defence Peptides; antimicrobial activity; antibiofilm activity; synergism; bacterial resistance
Online: 25 May 2018 (09:26:11 CEST)
Current research in the field of antimicrobials is focused on the development of novel antibiotics and antimicrobial agents to counteract the huge dilemma that the human population is mainly facing in regards to the rise of bacterial resistance and biofilm infections. Host Defense peptides (HDPs) are a promising group of molecules for antimicrobial development as they share unique characteristics suitable for antimicrobial activity including their broad spectrum of activity and potency against bacteria. AamAP1 is a novel HDP that was identified through molecular cloning from the venom of the North African scorpion Androctonus amoeruxi. In vitro antimicrobial assays revealed that the peptide displays moderate activity against different strains of Gram-positive and Gram-negative bacteria. Additionally, the peptide proved to be highly hemolytic and displaying significantly high toxicity against mammalian cells. In our study, a novel synthetic peptide analogue named A3 was designed from the naturally occurring scorpion venom host defense peptide. The design strategy depended on modifying the amino acid sequence of the parent peptide in order to increase its net positive charge, percentage helicity and optimize other physico-chemical parameters involved theoretically in HDPs activity. Accordingly, A3 was evaluated for its in vitro antimicrobial and anti-biofilm activity individually and in combination with four different types of conventional antibiotics against clinical isolates of multi-drug resistant (MDR) Gram-positive bacteria. A3 was also evaluated for its cytotoxicity against mammalian cells. A3 displayed potent and selective in vitro antimicrobial activities against a wide range of MDR Gram-positive bacteria. Our results also showed that combining A3 with conventional antibiotics displayed a synergistic mode of action which resulted in decreasing the MIC value for A3 peptide as low as 0.125 µM. These effective concentrations were associated with negligible toxicities on mammalian cells. In conclusion, A3 exhibits enhanced activity and selectivity when compared with the parent natural scorpion venom peptide. The combination of A3 with conventional antibiotics may be pursued as a potential novel treatment strategy against MDR and biofilm forming bacteria.
ARTICLE | doi:10.20944/preprints202310.1935.v1
Subject: Engineering, Bioengineering Keywords: External-hexagon implants; implant-abutment connections; electrolytic deposition; micro-gap; SEM; bacterial leakage
Online: 31 October 2023 (02:39:02 CET)
Purpose: The objective of the study was to qualitatively assess micro-gap dimensions, connecting fitting surface profile and bacterial leakage of machined and cast high gold alloy UCLA abutments, with or without electrodeposited gold coatings attached to external hexagon implants. Materials and methods: 16 plastic UCLA (PUCLA) and 5 machined cast-to UCLA (GUCLA) abutments were cast with a high gold content alloy. 10 were electrolytically gold plated (8 - PUCLA, 2 - GUCLA). All abutments were attached to implants giving 21 implant-abutment combinations (IACs). External perimeter micro-gaps measured with SEM under different illumination and magnification conditions were averaged over three regions. The IACs were examined for E.coli leakage following an initial sterility test. Disassembled combinations were examined with SEM and surface profiles qualitatively assessed. Results: External micro-gap measurements did not reflect the variable connecting surface profiles but average values < 3.5 μm were observed for all IACs. Bacterial transfer was observed in 3 of 5 PUCLA plated and 2 of 5 PUCLA non-plated IACs. No transfer occurred in the 3 GUCLA non-plated or 2 GUCLA plated IACs. Abutment connecting surfaces, both Au plated and not Au plated, showed plastic deformation (smearing) in variable mosaic patterns across the micro-gap. External micro-gap dimensions although not truly reflective of surface connecting profiles averaged < 3.5 μm measured under shadow eliminating silhouette illumination for both cast and pre-machined external hexagon abutments with and without Au plating. Conclusions: Micro-gap dimensions < 5 μm were obtained with both high noble metal cast and pre-machined external hexagon abutments with and without Au electrodeposited on the abutment connecting surface. Regions of intimate contact due to plastic deformation (smearing) of these surfaces was observed. A continuous smeared region around the circumference of the surfaces can provide an effective barrier to egress of E.coli bacteria from the internal regions of the implant under static loading.
ARTICLE | doi:10.20944/preprints202309.1997.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: ginsenoside; inflammatory bowel disease; tight junction protein; adherens junction protein; mucosal bacterial community
Online: 28 September 2023 (10:39:16 CEST)
Inflammatory bowel disease (IBD) comprises systemic inflammatory conditions primarily affecting the gastrointestinal tract, including Crohn's disease and ulcerative colitis. This research aims to analyze the clinical symptoms and pathogenesis of Dextran sodium sulfate (DSS)-induced canine IBD model, and evaluate the restorative effect of ginsenoside from a pathogenesis perspective. We established the DSS-induced canine IBD model and studied the pathological mechanisms. Additionally, we examined the therapeutic effect of ginsenosides by assessing the Canine Inflammatory Bowel Disease Activity Index (CIBDAI), C-reactive protein (CRP) levels, colonic tissue morphology, protein expression, and mucosal bacterial community analysis. Our findings revealed a total ginsenoside content of 22.7% in the ginsenoside extract. Animal experiments demonstrated that dogs with IBD exhibited decreased mental state, significantly increased CIBDAI and CRP levels, disrupted colonic epithelial tissue structure, decreased expression of mucin, tight junctions, and adherens junctions, as well as reduced diversity of the colonic mucosal bacterial community. Furthermore, correlation analysis highlighted a total of 38 bacterial strains correlated with physiological indices. Significantly, ginsenoside treatment could improve these symptoms and reverse the relative abundance of some bacterial communities. In conclusion, Alterations in the properties of the colonic mucus layer or the reduction of MUC2, its core component, in dogs with IBD can lead to bacterial penetration of the mucus layer and subsequent contact with intestinal epithelial cells, resulting in inflammation. Remarkably, ginsenoside intervention showcased the capacity to positively influence the relative abundance of bacteria and impact the colonic mucus layer properties, thereby offering promising prospects for IBD management and recovery.
ARTICLE | doi:10.20944/preprints202309.1003.v1
Subject: Public Health And Healthcare, Public, Environmental And Occupational Health Keywords: Bacterial profile; Antibiotic susceptibility; reproductive age females; risk factors; Urinary tract infection (UTI)
Online: 18 September 2023 (14:36:21 CEST)
Background: Urinary tract infection (UTI) is one of the commonest bacterial infections among reproductive age females. Untreated UTI in reproductive age female is associated with sexual dysfunction, cystitis, pyelonephritis and Pelvic inflammatory disease. At present, the antimicrobial resistance emergency has quadrupled worldwide and poses a serious threat to the treatment of patients. Thus, this study aimed to determine bacterial profile, antibiotic susceptibility pattern and associated risk factors of urinary tract infection among reproductive age females attending the Logbaba District Hospital Methods: A hospital-based cross-sectional study was conducted from January – July, 2023. Convenient sampling was employed to recruit 259 reproductive age females. Sociodemographic and risk factors information were obtained using a well-structured questionnaire. Mid-stream urine was collected and inoculated on cystine lactose electrolyte deficient media. Isolates were identified using API 20. Antibiotic sensitivity testing was performed using modified kirby-bauer susceptibility testing technique. Multivariate logistic regression model was used to assessed risk factors. A p-value < 0.05 was considered as statistically significant. Results: The overall prevalence of UTI among reproductive age females was 82/259 (31.66%). Symptomatic and asymptomatic patients reported a prevalence of 50/121(41.32%) and 32/138 (23.19%), respectively. Ages ranging from 21-30 years (AOR: 2.53 ,95% CI 1.32 – 4.43, p=0.006) and 31 – 40 years (AOR: 0.19 , 95% CI: 0.14- 0.54; p <0.0001), student (AOR: 1.8, 95% CI: 1.21 - 2.75; p = 0.010), history of UTI (5.34, 95% CI = 1.86 - 18.15; p = 0.03), symptomatic (AOR = 2.86, 95% CI1.78 - 4.67, p <0.0001) and secondary education (AOR: 0.13, 95% CI 0.08 - 0.32; p<0.0001) were predictors to UTI. Klebsiella Pneumoniae was the most frequent species 27 (32.9%), follow by E coli 22(26.8%), Staphylococcus aureus 16 (19.5%), CONS 8 (9.8%), Proteus mirabilis 6 (7.3 %) and Pseudomonas aeruginosa 3(3.7%). Majority of the isolates were sensitive to cefotaxime (87.80%), imipenem (85.7%), vancomycin (79.27%), Ofloxacillin (76.83%), Ceftriaxone (75.61%), Ciprofloxacin (74.39%), Gentamicin (71.95%) and Doxycycline (69.51%), and resistant to Amoxicillin (51.22%), cotrimoxazole (47.56%) and Azithromycin (31.71%) , All the isolates were multidrug drug resistant (100%) and Klebsiella Pneumoniae and E coli were the most multidrug drug resistant species Conclusion: In the present study, the prevalence of urinary tract infection among reproductive age females was high and considerably a high proportion of multidrug resistance was observed. This result will have a significant impact on the selection of appropriate antimicrobial agents for the treatment of urinary tract infection in the study area.
ARTICLE | doi:10.20944/preprints202308.0191.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: bladder; urinary tract infection; UPEC, bacterial biofilms; catheters; nitroxides; antibiotic resistance; fluoroquinolones; therapeutics
Online: 2 August 2023 (10:03:43 CEST)
Urinary tract infections (UTIs) are the second most common bacterial infection with high recurrence rates. A major causative agent of UTIs is uropathogenic Escherichia coli (UPEC), which can form persistent biofilms on urothelial surfaces and/or urinary catheters. Biofilms are inherently tolerant to antimicrobials, making them difficult to eradicate. Ciprofloxacin hybrids functionalised with nitroxides have previously shown enhanced biofilm eradication activity in vitro. Here, we evaluate a ciprofloxacin di-nitroxide hybrid (CDN11), previously reported to have antibiofilm activity against UPEC, as a potential UTI therapeutic in various infection models. We report potent CDN11 activity against mature biofilms formed by cystitis strain UTI89 inside polyethylene catheters. In infected human bladder cell monolayers, CDN11 afforded a 3-log reduction in UPEC colony forming units (CFU) compared to controls, including intracellular bacteria. Infected mouse bladders carrying biofilm-like intracellular UPEC reservoirs had reduced bacterial burdens following treatment with CDN11 ex vivo. Activity trends for CDN11 were comparable throughout all models, indicating that our testing pipeline was robust. New antimicrobial development is arduous and requires large investments of time and money. The pipeline described here could be readily used in testing new compounds, fast tracking the development of novel UTI therapeutics.
ARTICLE | doi:10.20944/preprints202305.0849.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Escherichia coli; bacterial transformation; plasmid-to-cell ratio; competent cell concentration; incubation time
Online: 11 May 2023 (11:49:13 CEST)
Bacterial transformation is the essential tool for introducing foreign DNA into bacterial cells in a host of recombinant technology applications useful for biomanufacturing and drug production. Thus far, chemically competent cells remain an important enabling technology for bacterial transformation given its facile transformation approach. However, many parameters affect transformation efficiency, and there is relatively little documentation of their cross-interacting effect in the literature. This work explores the roles played by incubation time on ice, competent cell concentration, and plasmid-to-cell ratio on transformation efficiency in Escherichia coli DH5α. Results revealed that increases in incubation time improve transformation efficiency, but 2 minutes incubation still yield appreciable efficiency. On the other hand, low concentration competent cells (106 CFU/mL) yielded significant improvement in transformation efficiency compared to high concentration competent cells (108 CFU/mL). In terms of plasmid-to-cell ratio, higher ratio increases transformation efficiency. Overall, bacterial transformation is incompletely understood particularly in the area of cross-interacting parameters. Experiments reported here revealed the possibility of short duration transformation where lower competent cell concentration and higher plasmid-to-cell ratio could improve transformation.