ARTICLE | doi:10.20944/preprints202106.0257.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Extracellular vesicles (EVs); mRNA; fungal pathogen; plant pathogen; Ustilago maydis
Online: 9 June 2021 (10:59:36 CEST)
Extracellular vesicles (EVs) can transfer diverse RNA cargo for intercellular signalling. EV-associated RNAs have been found in diverse fungi and were proposed to be relevant for pathogenesis in animal hosts. In plant-pathogen interactions, small RNAs are exchanged in a cross-kingdom RNAi warfare and EVs were considered to be a delivery mechanism. To extend the search for EV-associated molecules involved in plants-pathogen communication, we have characterised the repertoire of EV-associated mRNAs secreted by the maize smut pathogen, Ustilago maydis. For this initial survey, EVs were isolated from axenic filamentous cultures that mimic infectious hyphae. The EV-associated RNAs were resistant to degradation by RNases and the presence of intact mRNAs was evident. The set of mRNAs enriched inside EVs relative to the fungal cells are functionally distinct from those that are depleted from EVs, particularly overrepresented in metabolic enzyme activities. Intriguingly, mRNAs of some known effectors and other proteins linked to virulence were found in EVs. Furthermore, several mRNAs enriched in EVs are also upregulated during infection, suggesting that EV-associated mRNAs may participate in plant-pathogen interaction.
ARTICLE | doi:10.20944/preprints202009.0106.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Fish pathogen; host-pathogen interaction; proteomics; infection assays; virulence factors
Online: 4 September 2020 (12:51:22 CEST)
Piscirickettsia salmonis is an intracellular bacterial fish pathogen that causes piscirickettsiosis, a disease with numerous negative impacts in the Chilean salmon farming industry. Although transcriptomic studies of P. salmonis and its host have been performed, dual host-pathogen proteomic approaches during infection are still missing. Considering that gene expression not always corresponds with observed phenotype, and bacteriological culture studies inadequately reflect infection conditions, to improve the existing knowledge for the pathogenicity of P. salmonis we present here a global proteomic profiling of Salmon salar macrophage-like cell cultures infected with P. salmonis LF-89. The proteomic analyses identified several P. salmonis proteins from two temporally different stages of macrophages infection; some of them related to key functions for bacterial survival in other intracellular pathogens. Metabolic differences were observed in early-stage infection bacteria, compared to late-stage infections. Virulence factors related to membrane, LPS and surface component modifications, cell motility, toxins and secretion systems also varied between the infection stages. Pilus proteins, beta-hemolysin and the T6SS were characteristic of the early-infection stage, while fimbria, upregulation of 10 toxins or effector proteins, and the Dot/Icm T4SS were representative of the late-infection stage bacteria. Previously described virulence-related genes in P. salmonis plasmids were identified by proteomic assays during infection in SHK-1 cells, accompanied by an increase of mobile-related elements. By comparing the infected and un-infected proteome of SHK-1 cells, we observed changes in cellular and ROS homeostasis, innate immune response, microtubules and actin cytoskeleton organization and dynamics, alteration in phagosome components, iron transport and metabolism, and amino acids, nucleoside and nucleotide metabolism, together with an overall energy and ATP production alteration. Our global proteomic profiling and the current knowledge of the P. salmonis infection process allowed us to propose a model of the macrophage-P. salmonis interaction.
REVIEW | doi:10.20944/preprints202004.0097.v7
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: convalescent plasma; serology; pathogen reduction technologies; pathogen inactivation; COVID-19; SARS-CoV2
Online: 1 July 2020 (14:12:21 CEST)
Convalescent blood product therapy has been introduced since early 1900s to treat emerging infectious disease based on the evidence that polyclonal neutralizing antibodies can reduce duration of viremia. Recent large outbreaks of viral diseases for whom effective antivirals or vaccines are still lacking has revamped the interest in convalescent plasma as life-saving treatments. This review summarizes historical settings of application, and surveys current technologies for collection, manufacturing, pathogen inactivation, and banking, with a focus on COVID-19.
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: pathogen genomics; public health; bioinformatics
Online: 11 January 2020 (11:30:10 CET)
Public health agencies are increasingly using pathogen whole genome sequencing (WGS) to support surveillance and epidemiologic investigations. As access to WGS has grown, greater amounts of molecular data have helped improve our ability to detect outbreaks, investigate transmission chains, and explore large-scale population dynamics, such as the spread of antibiotic resistance. However, the wide adoption of WGS also poses challenges due to the amount of data generated and the need to transform raw data prior to analysis. This complexity means that public health agencies may need more advanced computational infrastructure, a broader technical workforce, and new approaches to data management and stewardship. As both a guide for how this development could occur, and a place to initiate discussion, we describe ten proposals for developing and supporting an informatics infrastructure for public health.
REVIEW | doi:10.20944/preprints202305.1972.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: transfusion; blood; pathogen reduction; emerging infectious diseases
Online: 29 May 2023 (05:05:21 CEST)
Emerging infectious disease threats are becoming more frequent due to various social, political and geographical pressures including increased human-animal contact, global trade, transportation and changing climate conditions. As a result, the threat that emerging agents can be spread by blood contact or transfusion of blood products also becomes increasingly problematic. Blood transfusion is essential in treating patients with anemia, blood loss, and other medical conditions. However, these lifesaving components can become a vector for spreading diseases, particularly to vulnerable populations. New methods have been implemented on a global basis for prevention of transfusion transmission via plasma, platelet, and whole blood products. Implementing proactive pathogen reduction methods can significantly reduce the likelihood of disease transmission via blood transfusion, even for newly emerging agents whose transmissibility and susceptibility are still being evaluated as they emerge. In this review, we consider the Mirasol PRT system for blood safety which is based on a photochemical method involving Riboflavin and UV light. We provide examples of how emerging threats such as Ebola, SARS-CoV-2, Hepatitis E, monkeypox and other agents have been evaluated in real time regarding effectiveness of this method for reducing the likelihood of disease transmission via transfusion. Keywords: transfusion; blood; pathogen reduction; emerging infectious diseases.
REVIEW | doi:10.20944/preprints202105.0033.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Campylobacter; Antimicrobial Resistance; Foodborne Pathogen; Animal Source
Online: 5 May 2021 (11:05:37 CEST)
Campylobacter is one of the major foodborne pathogens of concern in its growing trend of antimicrobial resistance. C. jejuni and C. coli are the major causative agents, with C. jejuni contributing to most of the cases in approximately 90% in the world. Infection is transmitted to humans due to consumption of contaminated food and water. Campylobacteriosis caused by C. jejuni is commonly presented with severe diarrhoea, abdominal pain, fever, headache, nausea, and vomiting with some extreme cases resulting in Guillain–Barré syndrome (GBS) and acute flaccid paralysis. Symptoms are severe in cases of children below 5 years, elderly and individuals who are immunocompromised. The infection is usually sporadic, and self-limiting and thus does not require antibiotics for treatment. Still, the antimicrobial resistance in Campylobacter is a major concern because of the transmission of resistance from animal sources to humans. This review highlights the recent epidemiology, geographical impact, resistance mechanisms, spread of Campylobacter spp. and the strategies to control the transmission of Campylobacter from veterinary sources and its antimicrobial resistance.
ARTICLE | doi:10.20944/preprints201901.0225.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: pathogen, climate change, sand, water quality, modeling
Online: 22 January 2019 (17:28:22 CET)
Humans may be exposed to microbial pathogens at recreational beaches via environmental sources, such as water, sand, and aerosols. Although infectious disease risk from exposure to waterborne pathogens has been an active area of research for decades, sand is a relatively unexplored reservoir of pathogens and fecal indicator bacteria (FIB). Beach sand and water habitats provide unique advantages and challenges to pathogen introduction, growth, and persistence, as well as continuous exchange between habitats. Models of FIB and pathogen fate and transport in sandy beach habitats can help predict the risk of infectious disease from recreational water use, but filling knowledge gaps such as decay rates and potential for microbial growth in beach habitats is necessary for accurate modeling. Climatic variability, whether natural or anthropogenically-induced, adds complexity to predictive modeling, but may increase human exposure to waterborne pathogens via extreme weather events, warming of water bodies and sea level rise in many regions. The popularity of human recreational beach activities, combined with predicted climate change scenarios, could amplify the risk of human exposure to pathogens and related illnesses. Other global change trends such as increased population growth and urbanization are expected to exacerbate contamination events and the predicted impacts of increasing levels of waterborne pathogens on human health. Such changes will alter microbial population dynamics in beach habitats, and will consequently affect the assumptions and relationships used in population models and quantitative microbial risk assessment (QMRA). Here, we discuss the literature on microbial population and transport dynamics in sand-water continuum habitats at beaches, how these dynamics can be modeled, and how climate change and other anthropogenic influences (e.g., land use, urbanization) should be considered when using and developing more holistic, beachshed-based models.
REVIEW | doi:10.20944/preprints202301.0416.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Inflammasome; NLRP3; periodontal disease; periodontal pathogen; IL-1β
Online: 23 January 2023 (15:07:31 CET)
Dr. Jurg Tschopp created the word "inflammasome" in 2002. Inflammasome activation and its function in disease processes have been the subject of significant investigation over the last 15 years. Four important inflammasomes have been identified: NLRP1, NLRP3, NLRC4, and AIM2. When these inflammasomes are activated, they process and secrete inflammatory cytokines such as IL-1b and IL-18, as well as cause pyroptosis, an inflammatory form of cell death. In this review, we will look at how these inflammasomes have been connected to Periodontitis pathogenesis.
REVIEW | doi:10.20944/preprints202209.0099.v1
Subject: Biology And Life Sciences, Virology Keywords: enterovirus; viral proteins; signalling pathways; host-pathogen interaction
Online: 7 September 2022 (04:41:56 CEST)
Enteroviruses are members of Pichornaviridae family consisting of human enterovirus group A, B, C, and D as well as nonhuman enteroviruses. Human enterovirus type 71 (EV71) has emerged as a major cause of viral encephalitis Hand, foot, and mouth disease (HFMD) in children worldwide especially in the Asia‐Pacific region. EV71 and coxsackievirus A16 are two viruses responsible for HFMD which are members of group A enterovirus. The identified EV71 receptors provide useful information for understanding viral replication and tissue tropism. Host factors interact with the internal ribosome entry site (IRES) of EV71 to regulate viral translation. However, the specific molecular features of the EV71 genome that determine virulence remain unclear. Although an EV71 vaccine has been currently approved, there is no effective therapy for treating EV71 infected patients. Therefore, understanding the host-pathogen interaction could provide the knowledge in viral pathogenesis and further benefit in the anti-viral therapy development. The aim of this study was to investigate the latest findings about the interaction of viral ligands to the host receptor as well as the activation of immune related signalling pathways for the activation of innate immunity and involvement of different cytokines and chemokines in the host pathogen interaction of EV71 along with interaction of viral proteins, mainly 2A and 3C protease, and Interferons production/signaling pathway and their inhibitory effects.
ARTICLE | doi:10.20944/preprints202110.0404.v1
Subject: Medicine And Pharmacology, Hematology Keywords: pathogen reduction; blood safety; platelet transfusion; INTERCEPT; plasma
Online: 27 October 2021 (12:27:33 CEST)
(1) Background: We reviewed the logistics of the implementation of pathogen inactivation (PI) using the INTERCEPT Blood System™ for platelets and the experience with routine use and clinical outcomes in the patient population at the Sírio-Libanês Hospital of São Paulo, Brazil. (2) Methods: Platelet concentrate (PC), including pathogen reduced (PR-PC) production, inventory management, discard rates, blood utilization, and clinical outcomes were analyzed over the 40 months before and after PI implementation. Age distribution and wastage rates were compared over the 10 months before and after approval for PR-PC to be stored for up to 7 days. (3) Results: A 100% PR-PC inventory was achieved by increasing double apheresis collections and production of double doses using pools of two single apheresis units. Discard rates decreased from 6% to 3% after PI implementation and further decreased to 1.2% after 7-day storage extension for PR-PCs. The blood utilization remained stable, with no increase in component utilization. A significant decrease in adverse transfusion events was observed after the PI implementation. (4) Conclusion: Our experience demonstrates the feasibility for Brazilian blood centers to achieve a 100% PR-PC inventory. All patients at our hospital received PR-PC and showed no increase in blood component utilization and decreased rates of adverse transfusion reactions.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: TMUV; emergent arboviruses; zoonosis; host-pathogen interactions; vector
Online: 9 July 2021 (07:36:16 CEST)
Reported for the first time in 1955 in Malaysia, Tembusu virus (TMUV) remained for a long time in the shadow of flaviviruses with human health importance such as dengue virus or Japanese encephalitis virus. However, since 2010 and the first large epidemic in duck farms in China, the threat of its emergence on a large scale in Asia or even its spillover into the human population is becoming more and more significant. This review aims to report current knowledge on TMUV from viral particle organization to the development of specific vaccine and therapeutic with a particular focus on host-virus interaction.
CONCEPT PAPER | doi:10.20944/preprints202105.0664.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Pathogen; Herd Immunity Threshold; R-naught; Infection dynamics
Online: 27 May 2021 (10:33:34 CEST)
In this article we have presented a new perception of herd immunity threshold (HIT) which considers that only a “band of population” are susceptible to any pathogenic infection. This is termed as the “effective herd immunity threshold” (EHIT) and the progression of the disease (caused by this pathogenic infection) is mainly determined by this EHIT value. We have argued here that this EHIT value (considering the immunity band picture in the population) will be substantially lower than the estimated canonical HIT values obtained from various existing models. We propose that the actual prediction of the disease progression should now be calculated using the EHIT values.
COMMUNICATION | doi:10.20944/preprints202004.0220.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: alphaherpesvirus; EHV-1; phosphatidylserine; inhibition; pathogen host interaction
Online: 14 April 2020 (08:54:01 CEST)
Exposure of phosphatidylserine (PS) in the outer leaflet of the plasma membrane is induced by infection with several members of the Alphaherpesvirinae subfamily. There is evidence that PS is used by the equine herpesvirus type 1 (EHV-1) during entry, but the exact role of PS and other phospholipids in the entry process remains unknown. Here, we investigated the interaction of differently charged phospholipids with virus particles and determined their influence on infection. Our data show that liposomes containing negatively charged PS or positively charged DOTAP [N-[1-(2,3-Dioleoyloxy)propyl]-N,N,N-trimethylammonium)] inhibited EHV-1 infection, while neutral phosphatidylcholine (PC) had no effect. Inhibition of infection with PS was transient, decreased with time, and was dose dependent. Our findings indicate that both cationic and anionic phospholipids can interact with the virus and reduce infectivity, while acting through different mechanisms. Charged phospholipids were found to have antiviral effects and can may be used to inhibit EHV-1 infection.
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.
REVIEW | doi:10.20944/preprints202201.0351.v1
Subject: Biology And Life Sciences, Forestry Keywords: Ash; ash dieback; disease management; Fraxinus excelsior; fungal plant pathogen; Hymenoscyphus fraxineus; mycology; plant pathology; plant pathogen; plant science; tree disease
Online: 24 January 2022 (11:50:43 CET)
Ash trees have considerable economic, cultural and environmental value on the island of Ireland. However, European ash (Fraxinus excelsior L.) is currently under threat from the invasive ascomycete pathogen Hymenoscyphus fraxineus. This pathogen is the causal agent of ash dieback disease, which was initially reported in Poland in 1992. Hymenoscyphus fraxineus has since spread across Europe and the first recorded case of the disease on the island of Ireland was in 2012 at a forestry plantation in Co. Leitrim. The pathogen is now present in all 26 counties in Ireland and 6 counties in Northern Ireland, and it is considered unfeasible to eradicate. The spread of ash dieback disease is reflected in recent policy changes, which focus on management rather than eradication strategies. Since the first formal description of H. fraxineus in 2006, considerable research efforts have been made by the international scientific community to understand the biology of the pathogen and to develop management strategies against it. This review provides an update of current knowledge of H. fraxineus biology and infection. We then explore examples of mitigation techniques that have been trialled in Europe, in order to identify strategies that are feasible for disease management at a local level on the island of Ireland. Finally, we outline five key avenues of research that have the potential to provide breakthroughs in methods to protect valuable F. excelsior resources.
ARTICLE | doi:10.20944/preprints202305.2270.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Sclerotinia stem rot; SSR; pathogen; canola/rapeseed; sclerotia; lesion
Online: 31 May 2023 (14:44:48 CEST)
Management of Sclerotinia stem rot (SSR) disease in Brassica napus is heavily reliant on prophylactic fungicide applications at flowering, which often provides inconsistent control depending on timing of ascospore release in the field and environmental conditions. Understanding host response to Sclerotinia sclerotiorum infection is essential for sustainable disease management in the future. This study determined the host response of nine B. napus varieties to four aggressive S. sclerotiorum isolates across two years by measuring four disease variables; area under the disease progress stairs (AUDPS), seed production, sclerotia number and average sclerotia weight. Brassica napus varieties varied greatly in their response to the four measured variables, with varieties producing the highest AUDPS not the same varieties that had the lowest seed production, the highest numbers of sclerotia or heaviest sclerotia. Repeating the experiment over two years using the same varieties and isolates identified the impact of environment as the most influential factor on measured disease variables, highlighting the complexity of disease responses to diverse isolates and host genotypes under different environments. It was recommended that both long-term (such as inoculum production) and short-term (such as seed production) disease outcomes be combined with lesion length measurement (i.e. AUDPS) for future host screening studies.
ARTICLE | doi:10.20944/preprints202301.0085.v1
Subject: Biology And Life Sciences, Virology Keywords: Biothermodynamics; Biosynthesis; Driving force; Life; Virus; Pathogen-host interaction
Online: 5 January 2023 (01:26:04 CET)
Viroids represent the simplest, but are also among the most interesting life-like forms. They represent a great problem in agriculture. Moreover, pathogens similar to viroids, such as the hepatitis Delta virus represent a risk for human health. Viroids encode no proteins, but are still able to hijack their host cells’ metabolism to perform multiplication. This paper attempts to reply three questions about viroids. First, how can viroids hijack their host cells’ metabolism, even though they encode no proteins to achieve this? Second, what advantages do viroids have from their simplicity? Third, what can viroids, as the simplest life-like forms, tell us about life as a natural phenomenon? These questions are discussed from the perspective of biothermodynamics. In order to do this, elemental composition, biosynthesis reactions and standard thermodynamic properties of viroids have been determined and analyzed.
REVIEW | doi:10.20944/preprints202112.0503.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Plant Pathogen; Biocontrol; Microbes; AMF; Bacteriophages; Microbiome; Sustainable strategies
Online: 31 December 2021 (10:45:32 CET)
Food security has become a major concern worldwide in recent years due to ever increasing population. Providing food for the growing billions without disturbing environmental balance is incessantly required in the current scenario. In view of this, sustainable modes of agricultural practices offer better promise and hence are gaining prominence recently. Moreover, these methods have taken precedence currently over chemical-based methods of pest restriction and pathogen control. Adoption of Biological Control is one such crucial technique that is currently in the forefront. Over a period of time, various biocontrol strategies have been experimented with and some have exhibited great success and promise. This review highlights the different methods of plant-pathogen control, types of plant pathogens, their modus operandi and various biocontrol approaches employing a range of microorganisms and their byproducts. The study lays emphasis on the use of upcoming methodologies like microbiome management and engineering, phage cocktails, genetically modified biocontrol agents and microbial volatilome as available strategies to sustainable agricultural practices. More importantly, a critical analysis of the various methods enumerated in the paper indicates the need to amalgamate these techniques in order to improve the degree of biocontrol offered by them.
ARTICLE | doi:10.20944/preprints201711.0182.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: RpoS; crystal structure; Legionella pneumophila; intracellular pathogen; regulatory factor
Online: 29 November 2017 (05:04:33 CET)
Legionella pneumophila RpoS (LpRpoS) is an alternative sigma factor of RNA polymerase (RNAP) essential for virulence and stress resistance. To investigate the mechanism of RpoS in the intracellular pathogen L. pneumophila, we determined the high-resolution crystal structure of the LpRpoS (residues 95-194) containing a partial region 1.2 and region 2. The structure of LpRpoS (residues 95-194) reveals that the conserved residues are critical for promoter melting, DNA and core RNAP binding. The differences in regulatory factor binding site between Escherichia coli RpoS and LpRpoS suggest that LpRpoS may employ a distinct mechanism to recruit alternative regulatory factors controlling transcription initiation.
REVIEW | doi:10.20944/preprints202206.0355.v1
Subject: Biology And Life Sciences, Parasitology Keywords: Leishmania; Human Pathogen; Targeting Metabolic Pathways; Repurposed Drugs; New Antileishmanials.
Online: 27 June 2022 (08:47:01 CEST)
Leishmaniasis is a tropical disease caused by a protozoan parasite Leishmania that is transmitted via infected female sandflies. At present, leishmaniasis treatment mainly counts on chemotherapy. The currently available drugs against leishmaniasis are costly, toxic, with multiple side effects, and limitations in the administration route. The rapid emergence of drug resistance has severely reduced the potency of anti-leishmanial drugs. As a result, there is a pressing need for the development of novel anti-leishmanial drugs with high potency, low cost, acceptable toxicity, and good pharmacokinetics features. Due to the availability of preclinical data, drug repurposing is a valuable approach for speeding up the development of effective antileishmanial through pointing to new drug targets in less time having low costs and risk. Metabolic pathways of this parasite play a crucial role in the growth and proliferation of Leishmania species during the various stages of their life cycle. Based on available genomics/proteomics information, known pathways-based (sterol biosynthetic pathway, purine salvage pathway, glycolysis, GPI biosynthesis, hypusine, polyamine biosynthesis) Leishmania-specific proteins could be targeted with known drugs that were used in other diseases, resulting in finding new promising anti-leishmanial therapeutics. The present review discusses various metabolic pathways of the Leishmania parasite and some drug candidates targeting these pathways effectively that could be potent drugs against leishmaniasis in the future.
ARTICLE | doi:10.20944/preprints202012.0511.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Antioxidant enzymes; hemibiotroph; reactive oxygen species; host-pathogen interaction; sporulation
Online: 21 December 2020 (11:23:57 CET)
Wheat blast caused by the hemibiotroph fungal pathogen Magnaporthe oryzae Triticum (MoT) pathotype, is a destructive disease of wheat in South America and Bangladesh. Generation of reactive oxygen species (ROS) is one of the defense responses in plants during the infection process by a pathogen. However, empirical evidence on regulation of ROS in wheat and other host and non-host plants towards MoT is limited. This study aimed to determine the susceptibility of some major cereals and weeds of Bangladesh and compare the antioxidant enzyme activities in host and non-host plants in response to artificial inoculation by MoT. Seedlings of wheat, maize, barley and swamp rice grass were susceptible to MoT and produced considerable number of conidia on infected leaves (host). Rice seedlings showed a resistant response in our laboratory conditions (non-host). The activities of ROS-detoxifying enzymes; catalase (CAT), ascorbate peroxidase (APX), Glutathione peroxidase (GPX), Glutathione S-transferase (GST), Peroxidase (POX) increased in all plants after inoculation by MoT with a few exceptions. Interestingly, an early and very high accumulation of CAT was observed within 24 hours of inoculation (hai) in wheat, barley, maize and swamp rice grass while H2O2 concentration was low during that time and immediately after that (24-48 hai). In contrast, an early and high accumulation of H2O2 was observed in rice at 48 hai with little CAT activity only at a late stage. The APX, GST and POD activity was also increased due to the inoculation of MoT at the early stage of infection in rice but were very high at the disease progression stage in wheat, barley, maize and swamp rice grass. GPX activity gradually decreased with the increase of time in rice. Taken together, our results suggest that a robust and late induction of most of the antioxidant enzyme activities occurs in susceptible/host plants whereas an early induction of antioxidant enzyme activities occurs in resistant/ non-host plant but with slow kinetics.
REVIEW | doi:10.20944/preprints202009.0748.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Verticillium dahliae; plant-pathogen interactions; disease resistance; integrated disease management
Online: 30 September 2020 (14:10:04 CEST)
Tomato (Solanum lycopersicum L.) is a valuable horticultural crop grown and consumed worldwide. Optimum production is hindered by several factors of which Verticillium dahliae, the cause of Verticillium wilt, is one of the major biological constraints in temperate production regions. V. dahliae is difficult to manage because it is a vascular pathogen, has a broad host range and worldwide distribution, and can persist in soil for years. Understanding the pathogen virulence and genetic diversity, host resistance, and plant-pathogen interactions can ultimately inform the development of integrated strategies to manage the disease. In recent years, considerable research has focused on providing new insight into these processes as well as the development and integration of environment-friendly management approaches. In this review, we discuss and summarize the recent findings on the race and population structure of V. dahliae; pathogenicity factors; host genes, proteins, and enzymes involved in defense; the emergent management strategies, and recent approaches to managing Verticillium wilt in tomatoes.
REVIEW | doi:10.20944/preprints202004.0061.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Forests; Emerging infectious diseases; Disease transmission; Human pathogen; Environmental impacts
Online: 6 April 2020 (14:06:44 CEST)
Deforestation and associated changing landscapes are major components of environmental changes, with important implications for ecosystem functioning and biodiversity conservation. Tropical forests are hot spots of biodiversity and provide multiple goods and ecosystem services which benefit people in many ways Forest also play an important role in health-related legends, myths, and fairy tales from all over the world, and are important sources of new potential emerging microbial threats to human. Although plausibly numerous abundant microbial forms with a forest origin may exist, our systematic literature review shows that forest-derived infection studies are relatively unexplored, and both taxonomically and geographically biased. Since biodiversity has been associated with emergence of novel infectious diseases at macro-scale, we describe the main biogeographical patterns in the emerging infection-biodiversity-forest loss nexus. Then, we illustrate four fine-scale case studies to decipher the underlying processes of increased infection risk in changing forest clearing landscapes. Finally, we identify scientific challenges and regional management measures required to mitigate these important new emerging threats.
REVIEW | doi:10.20944/preprints202210.0155.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Nitrate; Potassium; Necrotrophic fungi; Plant – Pathogen relation; CBL/CIPK; Jasmonic Acid
Online: 11 October 2022 (10:48:52 CEST)
In this opinion article, we have analyzed the relevancy of a hypothesis which is based on the idea that in Arabidopsis thaliana jasmonic acid (JA)-mediated defense system against necrotrophic fungi is weakened when NO3- supply is high. Such hypothesis is based on the fact that when NO3- supply is high, it induces an increase in the amount of bioactive ABA which induces the sequestration of the phosphatase ABI2 (PP2C) into the PYR/PYL/RCAR receptor. Consequently, the Ca sensors CBL1/9 - CIPK23 are not dephosphorylated by ABI2, thus remaining able to phosphorylate targets such as AtNPF6.3 and AtKAT1, a NO3- and K+ transporters respectively. Therefore, the impact of phosphorylation on the regulation of these two transporters, could 1) reduce NO3- influx as in its phosphorylated state AtNPF6.3 shifts to low capacity state and 2) increase K+ influx, as in its phosphorylated state KAT1 becomes more active. It is also well known that in the roots K+ loading in the xylem and its transport to the shoot is activated in the presence of NO3-. As such, the enrichment of plant tissues in K+ can impair jasmonic acid (JA) regulatory pathway and the induction of the corresponding biomarkers. The latter are known to be up-regulated under K+ deficiency and inhibited when K+ is resupplied. We therefore suggest that increased K+ uptake and tissue content induced by high NO3- supply modifies JA regulatory pathway, resulting in weakened JA-mediated plant’s defense system against necrotrophic fungi.
REVIEW | doi:10.20944/preprints201805.0378.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: annexins; inflammation; wound healing; host-pathogen interplay; drug target; translational research
Online: 27 May 2018 (11:32:34 CEST)
The vertebrate annexin superfamily (AnxA) consists of 12 members of a calcium (Ca2+) and phospholipid binding protein family which share a high structural homology. In keeping with this hallmark feature, annexins have been implicated in the Ca2+-controlled regulation of a broad range of membrane events. In this review, we identify and discuss several themes of annexin actions that hold a potential therapeutic value, namely the regulation of the immune response and the control of tissue homeostasis, and that repeatedly surface in the annexin activity profile. Our aim is to identify and discuss those annexin properties which might be exploited from a translational science and specifically clinical point of view.
REVIEW | doi:10.20944/preprints201802.0029.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: protease; plant; pathogen; defence; substrate; immunity; hypersensitive response; recognition; signalling; priming
Online: 5 February 2018 (04:11:42 CET)
Proteases are integral enzymes of the plant immune system. Multiple aspects of defence are regulated by proteases, including the hypersensitive response, pathogen recognition, priming and peptide hormone release. These processes are regulated by unrelated proteases residing at different subcellular locations. In this review we discuss ten prominent plant proteases contributing to the plant immune system, highlighting the diversity of roles they perform in plant defence.
REVIEW | doi:10.20944/preprints202305.0622.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Begomovirus; Whitefly; Viral genome; Viral transmission; Host-vector-pathogen interaction; Host defense
Online: 9 May 2023 (09:15:31 CEST)
Begomovirus infection in plant causes a great economic loss in many countries every year. Increasing rate of the infectivity of this single stranded DNA virus forces to study of its transmission in detail for the necessary researches regarding the control of this disease. This pathogenic virus is whitefly vector borne and transferred from one plant to another plant during the suckling of phloem sap by that vector. Viral transmissibility through this insect vector may depend on the genetic variations within the cryptic species groups. Two distinct categories of begomoviruses viz., bipartite and monopartite types consist of different genome organization. Virion particles modify the intracellular environment of the host according to their need of replication and survival. Viral replication takes place through RCR as well as RDR methods. Interplay among host, vector and pathogen is crucial for the establishment of infection. Several endosymbiotic organisms living within the insect vector also have vital role here. Being infected with this virus, host plant responds with defensive activities like TGS, PTGS, autophagy, hormonal regulation, metabolic alteration etc. However, virus also counteracts those through the manipulation of several pathways of cellular events. It is necessary to study in different directions and utilize advanced molecular biological techniques to develop begomovirus resistance within plants.
ARTICLE | doi:10.20944/preprints202207.0378.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: FHB; plant metabolomic; plant-pathogen interaction; barley; wheat; Brachypodium distachyon; pathway enrichment
Online: 26 July 2022 (03:22:55 CEST)
Background: Fusarium head blight (FHB) is a serious fungal disease of crop plants due to substantial yield reduction and production of mycotoxins in the infected grains. The breeding progress in increasing resistance with maintaining a high yield is not possible without a thorough examination of the molecular basis of plant immunity responses; Methods: LC-MS based metabolomics approaches powered by three-way ANOVA and differentially accumulated metabolites (DAMs) selection, correlation network and functional enrichment were conducted on grains of resistant and susceptible to FHB genotypes of barley and wheat as well as model grass Brachypodium distachyon (Bd) still poorly known at metabolomic level; Results: We selected common and genotype-specific DAMs in response to F. culmorum inoculation. Immunological reaction at metabolomic level was strongly diversified between resistant and susceptible genotypes. DAMs common for all tested species from porphyrins, flavonoids and phenylpropanoids metabolic pathways were highly correlated and reflects conservativeness in FHB response in Poaceae family. Resistant related DAMs belonged to different structural classes including tryptophan derived metabolites, pirimidines, amino acids proline and serine as well as phenylpropanoids and flavonoids. Physiological response to F. culmorum of Bd was close to barley and wheat genotypes however, metabolomic changes were strongly diversified. Conclusions: Combined targeted and untargeted metabolomics provides comprehensive knowledge about significant elements of plant immunity with potential of being molecular biomarkers of enhance resistance to FHB in grass family. Thorough examination of Bd21 metabolome in juxtaposition with barley and wheat diversified genotypes facilitate their setting as model grass for plant-microbe interaction.
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: global change; plant-herbivore interactions; plant-pathogen interactions; coexistence; antagonistic biotic interactions
Online: 23 July 2020 (10:36:26 CEST)
Indirect effects of global change via changing species interactions have been largely ignored in studies predicting global change impacts on ecosystems. Antagonistic biotic interactions, however, can strongly affect ecosystems and are likely to be affected by global change drivers themselves. We synthesize current knowledge on the impact of invertebrate herbivores and pathogens on plant productivity, diversity and community composition, and outline theory and expectations on how important global change drivers – nitrogen enrichment, climate change and elevated CO2, and plant and insect diversity loss, may affect enemy impact on plant communities. We illustrate that our ability to predict global change impact requires a holistic perspective, taking into account direct as well as indirect effects via the biotic component of ecosystems.
ARTICLE | doi:10.20944/preprints201912.0302.v1
Subject: Biology And Life Sciences, Virology Keywords: papillomavirus; feline; cat; felid; cancer; squamous cell carcinoma; phylogeny; discovery; pathogen; oncogenic
Online: 23 December 2019 (12:01:11 CET)
Papillomaviruses infect the skin and mucosal surfaces of diverse animal hosts with consequences ranging from asymptomatic colonization to highly malignant epithelial cancers. Increasing evidence suggests a role for papillomaviruses in the most common cutaneous malignancy of domestic cats, squamous cell carcinoma (SCC). Using total DNA sequencing we identified a novel feline papillomavirus in a nasal biopsy taken from a cat presenting with both nasal cavity lymphoma and recurrent squamous cell carcinoma affecting the nasal planum. We designate this novel virus as Felis catus papillomavirus 6 (FcaPV6). The complete FcaPV6 7453 bp genome was similar to those of other feline papillomaviruses and phylogenetic analysis revealed that it was most closely related to FcaPV3, although was distinct enough to represent a new viral species within the genus Taupapillomavirus. Archived excisional biopsy of the SCC, taken 20 months prior to presentation, was intensely positive on p16 immunostaining. FcaPV6, amplified using virus-specific, but not consensus, PCR was the only papillomavirus detected in DNA extracted from the SCC. Conversely, renal lymphoma, sampled at necropsy two months after presentation, tested negative on FcaPV6-specific PCR. In sum, using metagenomics we demonstrate the presence of a novel feline papillomavirus in association with cutaneous squamous cell carcinoma.
ARTICLE | doi:10.20944/preprints201911.0309.v1
Subject: Engineering, Bioengineering Keywords: in vitro diagnostics; microfluidics; full integration; lab-on-a-chip; pathogen detection
Online: 26 November 2019 (09:56:47 CET)
Microfluidics is facing critical challenges in the quest of miniaturizing, integrating, and automating in vitro diagnostics, including the increasing complexity of assays, the gap between the macroscale world and the microscale devices, and the diverse throughput demands in various clinical settings. Here a “3D extensible” microfluidic design paradigm that consists of a set of basic structures and unit operations was developed for constructing any application-specific assay. Four basic structures- check valve (in), check valve (out), double-check valve (in and out), and on-off valve, were designed to mimic basic acts in biochemical assays. By combining these structures linearly, a series of unit operations can be readily formed. We then proposed a “3D extensible” architecture to fulfill the needs of the function integration, the adaptive “world-to-chip” interface, and the adjustable throughput in the X, Y, and Z directions, respectively. To verify this design paradigm, we developed a fully integrated loop-mediated isothermal amplification microsystem that can directly accept swab samples and detect Chlamydia trachomatis automatically with a sensitivity one order higher than that of the conventional kit. This demonstration validated the feasibility of using this paradigm to develop integrated and automated microsystems in a less risky and more consistent manner.
ARTICLE | doi:10.20944/preprints201903.0234.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Batrachochytrium dendrobatidis; Chytridiomycosis; Amphibian pathogen; Amphibian disease; Culex quinquefasciatus, vector-borne disease
Online: 26 March 2019 (10:01:02 CET)
The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is an infectious disease responsible for the worldwide decline of amphibian species. To mitigate these declines, it is necessary to identify the various vectors by which the fungus can be transmitted between individuals and populations. The objective of this study was to determine whether adult female mosquitoes can carry and transfer Bd fungal cells. Mosquitoes were exposed to net soaked in a live Bd zoospore suspension to determine whether they are able to externally acquire the fungus. Another group was placed into containers with a sterile and Bd-inoculated agar plate to determine whether mosquitoes could transfer Bd between these surfaces. Bd DNA was found to be present on mosquito legs exposed to inoculated netting and agar plates suggesting that Bd can be transmitted by the mosquito over short distances This is the first study to demonstrate that an insect host may be a mechanical vector of Bd and suggests that we should begin to consider the role of mosquitoes in the dissemination and control of the fungus.
ARTICLE | doi:10.20944/preprints201809.0553.v1
Subject: Biology And Life Sciences, Virology Keywords: Citrus bark cracking viroid; differentially expressed genes; hop; pathogen; transcriptome analysis; viroids
Online: 28 September 2018 (05:26:31 CEST)
Viroids are smallest pathogen that consist of non-capsidated, single-stranded non-coding RNA replicons and exploits host factors for their replication and propagation. The severe stunting disease caused by Citrus bark cracking viroid (CBCVd) is a serious threat, which spread rapidly within hop gardens. In this study, we employed comprehensive transcriptome analyses to dissect host-viroid interactions and identify gene expression changes associated with disease development in hop. Our analysis revealed that CBCVd-infection resulted in the massive modulation of activity of over 2000 genes. Expression of genes associated with plant immune responses (protein kinase and mitogen-activated protein kinase), hypersensitive responses, phytohormone signaling pathways, photosynthesis, pigment metabolism, protein metabolism, sugar metabolism and modification and others were altered, which could be attributed to systemic symptom development upon CBCVd-infection in hop. In addition, genes encoding RNA-dependent RNA polymerase, pathogenesis-related protein, chitinase as well as those related to basal defense responses were up-regulated. The expression levels of several genes identified from RNA sequencing analysis were confirmed by qRT-PCR. Our systematic comprehensive CBCVd-responsive transcriptome analysis provides a better understanding and insights into complex viroid-hop plant interaction. This information will assist further in the development of future measures for the prevention of CBCVd spread in hop fields.
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/preprints202304.1160.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Cantharidin; Erythrocytes; Fish cell lines; Marine pathogen bacteria; Gilthead seabream (Sparus aurata); Aquaculture.
Online: 28 April 2023 (10:11:02 CEST)
Cantharidin, a toxic monoterpene secreted by blister beetles, has long been used in traditional Chinese and modern medicine for its unique properties. However, despite its widespread use, its effects on fish have not been studied in depth. The aim of this study was to evaluate the potential therapeutic applications of cantharidin in fish by examining its antioxidant, hemoagglutinating, hemolytic and cytotoxic activities at different concentrations (0, 0.625, 1.25, 2.5, 5 and 10 μg mL-1) in three different cell lines. In addition, the study explored the bactericidal and bacteriostatic properties of cantharidin against various fish pathogenic bacteria. The results revealed that there were no significant differences in antioxidant, hemagglutinating or hemolytic activities between the different concentrations of cantharidin tested. However, the study found that cantharidin exhibited dose- and time-dependent cytotoxicity in sea bream (Sparus aurata) erythrocytes and in SAF-1, PLHC-1 and Hela cell lines, resulting in morphological changes indicative of apoptosis. Interestingly, the highest dose of cantharidin tested demonstrated potent bactericidal activity against four marine fish opportunistic bacteria, including Vibrio harveyi, V. anguillarum, Photobacterium damselae and Tenacibaculum maritimum, but no statistically significant changes in bacteriostatic activity were observed against any of the bacteria tested. Overall, these results provide valuable information on the potential therapeutic applications of cantharidin in fish aquaculture. Further research is needed to fully understand the mechanisms of action and to explore possible preventive uses of cantharidin in fish.
ARTICLE | doi:10.20944/preprints202303.0461.v1
Subject: Biology And Life Sciences, Virology Keywords: Staphylococcus aureus; Small Colony Variants; Carnosine; RAW 264.7 murine macrophages; Host-Pathogen Interaction
Online: 27 March 2023 (12:16:26 CEST)
Phagosomal escape and intracellular survival, often accompanied by Small Colony Variants (SCVs) formation, are typical features of infections caused by S. aureus. The survival in macro-phages favours S. aureus dissemination and complicates treatment. RAW 264.7 murine macro-phages infected with S. aureus USA300 and treated with erythromycin and 20mM carnosine, alone and in combination, were used as experimental model. SCVs were isolated from all treat-ment conditions, but only those undergoing the pressure of combined erythromycin and carnosine for 48 hours were stable for at least six passages on blood agar. Nucleic acid extraction was car-ried out for S. aureus USA300 wild-type and stable SCVs. Whole Genome Sequencing (WGS) was performed using Illumina DNA Prep and Illumina MiSeq, and quantitative reverse transcription PCR was performed. WGS analysis did not yield mutations pointing to differences between S. au-reus USA300 and stable SCVs, therefore the focus was shifted to evaluating gene expression vari-ations. Genes such as zur, mntR, uhpt, fur, sdrE were shown to be significantly up-regulated in SCVs compared to S. aureus USA300 wild-type, suggesting a global change that allows adapta-tion to intracellular persistence, including protection from inflammatory response and evasion of the immune system.
REVIEW | doi:10.20944/preprints202210.0029.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: host-pathogen interactions; infection; viruses; translation; post-transcriptional modification; transfer RNA; bacteria; archaea
Online: 5 October 2022 (09:47:07 CEST)
Viruses feature an evolutionary shaped minimal genome that is obligately dependent on the cellular transcription and translation machinery for propagation. To suppress host cell immune responses and ensure efficient replication, viruses employ numerous tactics to favor viral gene expression and protein synthesis. This necessitates a carefully balanced network of virus- and host-encoded components, of which the RNA-based regulatory mechanisms have emerged as particularly interesting albeit insufficiently studied, especially in unicellular organisms. Here, recent advances that further our understanding of RNA-based translation regulation, mainly through post-transcriptional chemical modification of ribonucleosides, codon usage, and (virus-encoded) transfer RNAs, will be discussed in the context of viral infection.
ARTICLE | doi:10.20944/preprints202105.0538.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Lophelia pertusa; Haplosporidia; Vibrio; Rickettsiales-like organisms; Histology; PCR; Pathogen; Cold-water corals
Online: 24 May 2021 (08:20:11 CEST)
Temperature and pH can expedite the ability of pathogens to cause diseases in cold-water corals (CWCs). The present study employed a combination of histology and polymerase chain reaction diagnostic techniques to investigate potential pathogens present in the CWCs Lophelia pertusa and Madrepora oculata in the Porcupine Bank Canyon (PBC), NE Atlantic. No pathogen was observed in the Madrepora samples. Neither histology nor standard PCR detected Vibrio spp. in the corals, although using Illumina technology, V. shilonii was observed in some L. pertusa samples in low abundances (0.22%). A Rickettsiales-like organisms (RLOs) occurred at a prevalence of 8.0% and at a low infection intensity of 1 - 4. Lophelia showed a few RLOs infection from the PBC canyon head (2.7%) and high infections in the south branch (5.3%). Similarly, unidentified cells observed in L. pertusa from the south branch (4.0%) were more common than those found in the canyon head (1.3%) with a prevalence of 5.3%. Although the route of pathogen infection is unclear, a likely mode of entry could be associated with particulate availability and the feeding strategies of the scleractinian corals. This suggest that L. pertusa invests energy into an enhanced immune function and reduced susceptibility to global pathogens despite a changing ocean environment.
ARTICLE | doi:10.20944/preprints202011.0306.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Staphylococcus aureus; osteoblast-like cells; internalization; inflammation; immune system; host-pathogen interaction; cytokines
Online: 10 November 2020 (12:06:04 CET)
Staphylococcus aureus is a Gram-positive bacterium causing a range of mild to life-threatening infections including bone infections such as osteomyelitis. S. aureus is able to invade and persist within non-professional phagocytic cells such as osteoblasts. In the present study four different S. aureus strains, 2SA-ST239-III, 5SA-ST5-II, 10SA-ST228-I, and 14SA-ST22-IVh were tested for their ability to modulate cell viability in MG-63 osteoblast-like cells following a successful invasion and persistence. Methicillin-sensitive S. aureus (MSSA) ATCC-12598-ST30 was used as control. Despite the demonstrated similar abilities of internalization and persistence of ATCC-12598-ST30, 2SA-ST239-III, and 14SA-ST22-IVh strains in MG-63 osteoblast-like cells under our experimental conditions, we demonstrated that the decrease in cell viability was due to the different behavior of the considered strains, with the number of intracellular bacteria playing a limited role. We focused our attention on different cellular biochemical functions related to inflammation, cell metabolism, and oxidative stress during osteoblast infections. We were able to show that: 1) ATCC-12598-ST30 and 2SA-ST239-III were the only two clones able to persist and maintain their number into the cellular hostile environment during the entire period of infection; 2) 2SA-ST239-III was the only clone able to significantly increase the gene expression (3 and 24 h) and protein secretion (24 h) of both interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in MG-63 osteoblast-like cells; 3) the same clone determined a significant up-regulation of transforming growth factor-β1 (TGF-β1) and the metabolic marker glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNAs at 24 h post infection; 3) neither the MSSA nor the four MRSA strains induced oxidative stress phenomena in MG-63 cells, although a very different expression pattern towards nuclear factor E2-related factor 2 (Nrf2) and its downstream gene heme oxygenase 1 (HO-1) activation was observed among the different clones. Our results can open a new way of considering therapies, going in the direction of an individualized therapeutic strategy that should take into account the difference existing between MSSA and MRSA as well as the distinctive features of the different clones. Not only, therefore, a different antibiotic approach but also a starting point for considering different host factors, i.e. the modulation of specific cytokines such as IL-6, TNF-α, and TGF-β1.
REVIEW | doi:10.20944/preprints202010.0066.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Vitis vinifera; Plasmopara viticola; plant-pathogen interaction; proteomics; defence-related proteins, ETS, ETI
Online: 5 October 2020 (10:58:33 CEST)
Grapevine is one of the most relevant crops in the world being used for economically important products such as wine. Yet, relevant grapevine cultivars are heavily affected by diseases such as the downy mildew disease caused by Plasmopara viticola. Improvements on grapevine resistance are made mainly by breeding techniques where resistance traits are introgressed into cultivars with desired grape characteristics. However, there is still a lack of knowledge on how resistant or tolerant cultivars tackle the P. viticola pathogen. In this study, using a shotgun proteomics LC-MS/MS approach, we unravel the protein modulation of a highly tolerant grapevine cultivar, V. vinifera ‘Regent’, in the first hours post inoculation (hpi) with P. viticola. At 6 hpi, proteins related to defence and to response to stimuli are negatively modulated while at 12 hpi there is an accumulation of proteins belonging to both categories. The co-occurrence of effector-triggered susceptibility (ETS) and effector-triggered immunity (ETI) is detected at both time-points, showing that these defence processes present high plasticity. The results obtained in this study unravel the tolerant grapevine defence strategy towards P. viticola and may provide valuable insights on resistance associated candidates and mechanisms, which may play an important role in the definition of new strategies on breeding approaches.
REVIEW | doi:10.20944/preprints202007.0528.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: In vitro; in vivo; animal model; Malassezia; infection; host-pathogen interaction; Galleria mellonella
Online: 22 July 2020 (11:34:57 CEST)
Malassezia is a lipid-dependent genus of yeasts known for being an important part of the skin mycobiota. These yeasts have been associated in the development of skin disorders and cataloged as a causal agent of systemic infections under specific conditions, making them opportunistic pathogens. Little is known about the host-microbe interaction of Malassezia spp., and unraveling this implies the implementation of infection models. In this mini review we present different models that have been implemented in the fungal infections study with greater attention in Malassezia spp. infections. These models range from in vitro (cell cultures and ex vivo tissue), to in vivo (murine models, rabbits, guinea pigs, insects, nematodes, and amoebas). We additionally highlight the alternative models that reduce the use of mammals as model organisms, which have been gaining importance in the study of fungal host-microbe interactions. This is due to the fact that these systems have shown to have reliable results, which correlate with those obtained from mammalian models. Example of alternative models are Caenorhabditis elegans, Drosophila melanogaster, Tenebrio molitor, and Galleria mellonella. These are invertebrates that have been implemented in the study of Malassezia spp. infections in order to identify differences in virulence between Malassezia species.
REVIEW | doi:10.20944/preprints202005.0041.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Vimentin; Cell surface vimentin; SARS-CoV; Vimentin-pathogen interactions; Anti-vimentin autoantibodies; Inflammation
Online: 3 May 2020 (09:00:43 CEST)
Vimentin is an intermediate filament protein that plays key roles in integration of cytoskeletal functions, and therefore in basic cellular processes such as cell division and migration. Consequently, vimentin has complex implications in pathophysiology. Vimentin is required for a proper immune response, but it can also act as an autoantigen in autoimmune diseases or as a damage signal. Although vimentin is a predominantly cytoplasmic protein, it can also appear at extracellular locations, either in a secreted form or at the surface of numerous cell types, often in relation to cell activation, inflammation, injury or senescence. Cell surface targeting of vimentin appears to associate with the occurrence of certain posttranslational modifications, such as phosphorylation and/or oxidative damage. At the cell surface, vimentin can act as a receptor for bacterial and viral pathogens. Indeed, vimentin has been shown to play important roles in virus attachment and entry of severe acute respiratory syndrome-related coronavirus (SARS-CoV), dengue and encephalitis viruses, among others. Moreover, the presence of vimentin in specific virus-targeted cells and its induction by proinflammatory cytokines and tissue damage contribute to its implication in viral infection. Here, we recapitulate some of the pathophysiological implications of vimentin, including the involvement of cell surface vimentin in interaction with pathogens, with a special focus on its role as a cellular receptor or co-receptor for viruses. In addition, we provide a perspective on approaches to target vimentin, including antibodies or chemical agents that could modulate these interactions to potentially interfere with viral pathogenesis, which could be useful when multi-target antiviral strategies are needed .
ARTICLE | doi:10.20944/preprints201809.0525.v1
Subject: Biology And Life Sciences, Virology Keywords: hepatitis E virus; innate immunity; interferon response; JAK/STAT pathway; zoonosis; emerging pathogen
Online: 27 September 2018 (03:34:49 CEST)
Hepatitis E virus (HEV) is responsible for large waterborne epidemics of hepatitis in endemic countries and is an emerging zoonotic pathogen worldwide. In endemic regions, HEV-1 or HEV-2 genotypes are frequently associated with fulminant hepatitis in pregnant women, while with zoonotic HEV (HEV-3 and HEV-4), chronic cases of hepatitis and severe neurological disorders are reported. Hence, it is important to characterize the interactions between HEV and its host. Here, we investigated the ability of the non-structural polyprotein encoded by the first open reading frame (ORF1) of HEV to modulate the host early antiviral response and in particular the type I interferon (IFN-I) system. We found that the amino-terminal region of HEV-3 ORF1 (MetPCP), containing a putative methyltransferase (Met) and a papain-like cysteine protease (PCP) functional domain, inhibited IFN-stimulated response element (ISRE) promoter activation and the expression of several IFN-stimulated genes (ISGs) in response to IFN-I. We showed that the MetPCP domain interfered with the Janus kinase (JAK)/signal transducer and activator of transcription protein (STAT) signalling pathway by inhibiting STAT1 nuclear translocation and phosphorylation after IFN-I treatment. By contrast, MetPCP had no effect on STAT2 phosphorylation and a limited impact on the activation of the JAK/STAT pathway after IFN-II stimulation. This inhibitory function seemed to be genotype-dependent as MetPCP from HEV-1 had no significant effect on the JAK/STAT pathway. Overall, this study provides evidence that the predicted MetPCP domain of HEV ORF1 antagonises STAT1 activation to modulate the IFN response.
REVIEW | doi:10.20944/preprints202106.0204.v1
Subject: Public Health And Healthcare, Public, Environmental And Occupational Health Keywords: One Health; Planetary Health; Pandemics; Ecology; Evolution; Environment; Climate change; Biodiversity loss; Emergence; Pathogen
Online: 8 June 2021 (09:34:57 CEST)
The implementation of One Health/EcoHealth/Planetary Health approaches has been identified as key (i) to address the strong interconnections between risk for pandemics, climate change and biodiversity loss, and (ii) to develop and implement solutions to these interlinked crises. As a response to the multiple calls of scientists in that direction, we have put forward seven long term research questions regarding COVID-19 and emerging infectious diseases (EIDs) that are based on an effective integration of environmental, ecological, evolutionary, and social sciences to better anticipate and mitigate EIDs. Research needs cover the social-ecology of infectious disease agents, their evolution, the determinants of susceptibility of humans and animals to infections, and the human and ecological factors accelerating infectious disease emergence. For comprehensive investigation, they include the development of nature-based solutions to interlinked global planetary crises, addressing ethical and philosophical questions regarding the relationship of humans to nature and regarding transformative changes to safeguard the environment and human health. In support of this research, we propose the implementation of innovative multidisciplinary facilities embedded in social-ecosystems locally: the “ecological health observatories” and the “living laboratories”. This work has been carried out in the frame of the EC project HERA (www.HERAresearchEU.eu) that aims to set the priorities for an environment, climate and health research agenda in the EU by adopting a systemic approach in the face of global environmental change.
REVIEW | doi:10.20944/preprints202012.0554.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: microbiome; vectorial capacity; density; competence; biting; extrinsic incubation period; longevity; mosquito; symbiosis; pathogen transmission
Online: 22 December 2020 (10:49:13 CET)
Microbiome research has gained considerable interest due to the emerging evidence of its impact on human and animal health. Similar to higher organisms, the gut-associated microbiota of mosquitoes affect host fitness and other phenotypes. It is now well established that microbes can alter pathogen transmission in mosquitoes, either positively or negatively, and avenues are being explored to exploit microbes for vector control. However, less attention has been paid to how microbiota affect phenotypes that impact vectorial capacity. Several mosquito and pathogen components, such as vector density, biting rate, survival, vector competence and pathogen extrinsic incubation period all influence pathogen transmission. Interestingly, the mosquito gut-associated microbes can impact each of these components, and therefore ultimately modulate vectorial capacity. Promisingly, this expands the options available to exploit microbes for vector control by also targeting parameters that affect vectorial capacity. However, there are still many knowledge gaps in the biology of the mosquito – microbe symbiosis that need to be addressed in order to understand these interactions more thoroughly and exploit them efficiently. Here, we review current evidence of the impacts of the microbiome on aspects of vectorial capacity highlighting opportunities for novel vector control strategies and areas where further studies are required.
REVIEW | doi:10.20944/preprints202010.0639.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Plants; polyamines; abiotic stresses; biotic stresses; transgenic plants; Plant-pathogen interaction; Plants-fungal interaction
Online: 30 October 2020 (13:10:51 CET)
The biotic and abiotic stresses are the main causes of the loss of agricultural crops productivity, their normal growth and development in the environment. It has been calculated that two-thirds of the major crops are frequently lost due to adverse environmental conditions. The productivity of crops under unfavorable environmental stresses is apparently the main challenge to the breeders and farmers where polyamines (PAs) play diverse roles in environmental stimuli. PAs (putrescine, spermidine, and spermine) are low molecular weight positively charge compounds have the active potential power to negative charge molecules (DNA, RNA, and proteins) is widely distributed in all living organisms. Evidence showed that PAs contribute a lot of different physiological and biological functions, such as cell growth and development, controlling the cell cycle, involve in gene expression, cell signaling, replication, transcription, translation, and membrane stabilization. Naturally occurring polyamines activity acuminated to their involvement with different biotic and abiotic stresses and contribute to the survival of the plant in the environment. Here, we have described the potential mechanisms, synthesis, and various roles of PAs during stresses tolerant and disease resistance.
ARTICLE | doi:10.20944/preprints201809.0500.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Actinobaculum; urinary tract infection; biofilm; catheter; CAUTI; host-pathogen interaction; proteome; polymicrobial; metabolism; uropathogen
Online: 26 September 2018 (06:07:28 CEST)
Actinobaculum massiliense, a Gram-positive anaerobic coccoid rod colonizing the human urinary tract, belongs to the taxonomic class of Actinobacteria. We identified A. massiliense as a cohabitant of urethral catheter biofilms (CB). The CBs also harbored common uropathogens such as Proteus mirabilis and Aerococcus urinae, supporting the notion that A. massiliense is adapted to a life style in polymicrobial biofilms. We isolated a strain from an agar colony derived from a clinical sample. Using 16S rRNA gene sequencing and shotgun proteomics, we identified and characterized A. massiliense, comparing the isolate grown in vitro and four clinical ‘in vivo’ samples. Based on abundances of proteins in the in vivo milieu, we assessed their functions related to nutrient import and responses to hostile host conditions characterized by neutrophil infiltration. Two putative subtilisin-like proteases and a heme/oligopeptide transporter were highly expressed in vivo and are perhaps important for survival in the host milieu. The uptake of xylose/glucuronate and oligopeptides apparently enables feeding metabolites into mixed acid fermentation and peptidolysis pathways, respectively, to generate energy. A putative polyketide synthase which may generate a secondary metabolite interacting with either the host or co-colonizing microbes was identified. The enzyme may contribute to A. massiliense persistence in CBs.
ARTICLE | doi:10.20944/preprints202210.0151.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: host shifts; cross-species transmission; rabies; genetic divergence; host-pathogen interaction; niche overlap; range overlap
Online: 11 October 2022 (10:37:48 CEST)
Most pathogens are capable of infecting multiple host species and such cross-species transmission (CST) can have dramatic consequences, as highlighted by recent disease emergence events affecting human, animal and plant health. Understanding the ecological and evolutionary factors that constrain or facilitate the ability of disease agents to infect and establish in a novel host is therefore a timely and important research area. Previous work across different pathogens, including rabies virus (RABV), found that increased evolutionary distance between hosts reduces the frequency of cross-species transmission and of permanent host shifts. However, whether this effect of host relatedness still holds for transmission among recently diverged hosts, and the importance of this effect relative to other predictors, is not well understood. We addressed this question by quantifying the CST frequency of RABV between North American bat species within the genus Myotis, using a multi-decade data set containing 128 nucleoprotein (N) sequences from ten host species. For comparison, we also conducted an equivalent analysis of a RABV dataset from North American bat species comprising nine genera. We found that at the within genus scale, host relatedness failed to explain the frequency of CST events. However, CST frequency increased with overlap in species’ host range. Moreover, we found evidence of CST occurring among a higher proportion of species, and CST more frequently resulting in sustained transmission in the novel host in the Myotis dataset compared to the multi-genus dataset. Our results suggest that among recently diverged species, the ability to infect a novel host is no longer restricted by physiological barriers but instead is limited by physical contact. Our results improve predictions of where future CST events for RABV might occur and clarify the relationship between host divergence and pathogen emergence.
ARTICLE | doi:10.20944/preprints202111.0240.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: pathogen detection, bacteria quantification, dark field imaging, hydrodynamic diameter, E.coli, biosensing, water contamination, magnetic microparticles
Online: 12 November 2021 (17:09:40 CET)
In this paper, we present a method for detecting and quantifying pathogens in water samples. The method proposes a portable dark field imaging and analysis system for quantifying E. coli concentrations in water after being labeled with magnetic particles. The system utilizes the tracking of moving micro/nano objects close to or below the optical resolution limit confined in small sample volumes (~ 10 µl). In particular, the system analyzes the effect of volumetric changes due to bacteria conjugation to magnetic microparticles (MP) on their Brownian motion while being suspended in liquid buffer solution. The method allows for a simple inexpensive implementation and the possibility to be used as point-of-need testing system. Indeed, a work-ing prototype is demonstrated with the capacity of quantifying E. coli colony forming units (CFU) at a range of 1x10³ - 6x10³ CFU/mL.
COMMUNICATION | doi:10.20944/preprints202004.0253.v1
Subject: Biology And Life Sciences, Virology Keywords: Genomic Epidemiology; GenomeTrakr; microbial pathogen surveillance, NCBI submission; whole genome sequencing; QA/QC; One Health
Online: 16 April 2020 (05:26:42 CEST)
The holistic approach of One Health, which sees human, animal, plant, and environmental health as a unit, rather than discrete parts, requires not only interdisciplinary cooperation, but standardized methods for communicating and archiving data, enabling participants to easily share what they have learned and allow others to build upon their findings.Ongoing work by NCBI and the GenomeTrakr project illustrates how open data platforms can help meet the needs of federal and state regulators, public health laboratories, departments of agriculture, and universities. Here we describe how microbial pathogen surveillance can be transformed by having an open access database along with Best Practices for contributors to follow. First, we describe the open pathogen surveillance framework, hosted on the NCBI platform. We cover the current community standards for WGS quality, provide an SOP for assessing your own sequence quality and recommend QC thresholds for all submitters to follow. We then provide an overview of NCBI data submission along with step by step details. And finally, we provide curation guidance and an SOP for keeping your public data current within the database. These Best Practices can be models for other open data projects, thereby advancing the One Health goals of Findable, Accessible, Interoperable and Re-usable (FAIR) data.
ARTICLE | doi:10.20944/preprints202305.0911.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: COVID–19; all-cause mortality; single year of age; gender; complex system; pathogen interference; seasonality; small RNAs
Online: 12 May 2023 (09:01:29 CEST)
Since 2020 COVID-19 has caused serious mortality around the world. Given the ambiguity in es-tablishing COVID-19 as the direct cause of death we first investigate the effects of age and sex upon all-cause mortality during 2020 and 2021 in England and Wales. Since infectious agents have their own unique age profile for death, we explore several methods to adjust single year of age deaths in England and Wales during 2019 (the pre-COVID-19 base year) to a pathogen-neutral single year of age baseline. This adjusted base year is then used to confirm the widely reported higher deaths in males for most ages above 43 years in both 2020 and 2021. During 2020 (+ COVID-19 but no vac-cination) both male and female population-adjusted deaths were significantly increased above age 35. A significant reduction in all-cause mortality among both males and females aged 75+ could be demonstrated in 2021 during widespread COVID–19 vaccination, however, below age 75 deaths progressively increased. This finding arises from a mix of vaccination and year of age profiles of deaths for the different SARS-CoV-2 variants. In addition, specific effects for age around puberty were demonstrated where females had higher deaths rather than males. There is evidence that year-of-birth cohorts may also be involved, indicating that immune priming to specific pathogen outbreaks in the past may lead to lower deaths for some birth cohorts. To specifically identify the age profile for the COVID-19 variants in 2020 to 2023, we employ the proportion of total deaths at each age which are potentially due to or ‘with’ COVID-19. The original Wuhan strain, and the Alpha variant show somewhat limited divergence in the age profile with the Alpha variant shifted to a moderately higher proportion of deaths below age 84. The Delta variant specifically targeted persons below age 65. The Omicron variants showed significantly lower proportion of overall mortality, with markedly higher relative proportion of deaths above age 65 steeply increasing with age to a maximum around 100 years of age. A similar age profile for the variants can be seen in the age-banded deaths in US states – although slightly obscured by using age bands rather than single year of age. However, the US data shows that higher male deaths are greatly dependent on age and the COVID-variant. Deaths determined as ‘due to’ COVID-19 (as opposed to ‘involving’ COVID-19) in England and Wales were especially over-estimated in 2021 relative to the change in all-cause mortality. This arose as a by-product of an increase in COVID-19 testing capacity in late 2020. Potential structure-function mechanisms for the year of age specificity of SARS-CoV-2 var-iants are discussed. The question is posed as to whether vaccines based on different variants carry the specific age profile through into the vaccine.
ARTICLE | doi:10.20944/preprints202304.0248.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: COVID–19; vaccination; all-cause mortality; age; gender; complex system; pathogen interference; seasonality; miRNAs; nonspecific vaccine effects
Online: 12 April 2023 (07:06:23 CEST)
All vaccines exhibit both specific and non-specific effects. The specific effects are measured by the efficacy against the target pathogen, while the non-specific effects can be detected by the change in all-cause mortality . All-cause mortality data (gender, age band, vaccination history, month of death) between January 2021 and May 2022 was compiled by the Office for National Statistics. COVID–19 vaccination gave good protection on many occasions but less so for younger ages. Each gender and age group shows its own unique vaccination benefit/disbenefit time profile. Individuals are free to make vaccination decisions. For example, women aged 18-39 show a cohort who do not progress beyond the first or second dose. The all-cause mortality outcomes for the Omicron variant showed a very poor response to vaccination with 70% of sex/age/vaccination stage/month combinations increasing all-cause mortality, probably due to unfavorable antigenic distance between the first-generation vaccines and this variant, and additional non-specific effects. The all-cause mortality outcomes of COVID–19 vaccination is far more nuanced than have been widely appreciated, and virus vector appear better than the mRNA vaccines in this specific respect. The latter are seemingly more likely to increase all-cause mortality especially in younger age groups. An extensive discussion/literature review is included to provide potential explanations for the observed unexpected vaccine effects.
COMMUNICATION | doi:10.20944/preprints202201.0108.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Acinetobacter baumannii; antimicrobial resistance; circular dichroism spectroscopy; efflux protein; efflux pump; foodborne pathogen; hospital-acquired infection; polyamine
Online: 10 January 2022 (12:19:07 CET)
The aim of this work was to test polyamines as potential natural substrates of the Acinetobacter baumannii chlorhexidine efflux protein AceI using near-UV synchrotron radiation circular dichroism (SRCD) spectroscopy. The Gram-negative bacterium A. Baumannii is a leading cause of hospital-acquired infections and an important foodborne pathogen. A. Baumannii strains are becoming increasingly resistant to antimicrobial agents, including the synthetic antiseptic chlorhexidine. AceI was the founding member of the recently recognised PACE family of bacterial multidrug efflux proteins. Using the plasmid construct pTTQ18-aceI(His6) containing the A. Baumannii aceI gene directly upstream from a His6-tag coding sequence, expression of AceI(His6) was amplified in E. coli BL21(DE3) cells. Near-UV (250-340 nm) SRCD measurements were performed on detergent-solubilised and purified AceI(His6) at 20 °C. Sample and SRCD experimental conditions were identified that detected binding of the triamine spermidine to AceI(His6). In a titration with spermidine (0-10 mM) this binding was saturable and fitting of the curve for the change in signal intensity produced an apparent binding affinity (KD) of 3.97 +/- 0.45 mM. These SRCD results were the first experimental evidence obtained for polyamines as natural substrates of PACE proteins.
ARTICLE | doi:10.20944/preprints201901.0157.v1
Subject: Medicine And Pharmacology, Veterinary Medicine Keywords: Cetacean Morbillivirus; Canine Distemper Virus; Rinderpest Virus; viral phylogeny; viral evolution; Host-pathogen interactions; cetaceans; aquatic mammals
Online: 16 January 2019 (08:38:32 CET)
Cetacean Morbillivirus, the most relevant pathogen impacting the health and conservation of cetaceans worldwide, has shown in recent years an increased tendency to cross “interspecies barriers”, thereby giving rise to disease and mortality outbreaks in free-ranging dolphins and whales. The present article deals with the evolutionary “trajectories” of this viral pathogen, likely originating from Rinderpest Virus, along with its “journey” from land to sea (and viceversa), mimicking that of cetaceans' terrestrial ancestors.
REVIEW | doi:10.20944/preprints202305.0979.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: Tuberculosis; ESAT-6; ESX-1; virulence factors; T7SS; PhoPR signal transduction; host-pathogen interactions; TB vaccines; TB diagnosis
Online: 15 May 2023 (05:30:34 CEST)
Mycobacterium tuberculosis (Mtb) the causative agent of human tuberculosis (TB) is one of the most successfully adapted-human pathogens. Human-to-human transmission occurs at high rates through aerosols containing bacteria, but the pathogen evolved prior to the establishment of crowded populations. Mtb has developed a particular strategy to ensure persistence in the host until an opportunity for transmission arise. It has refined its lifestyle to obviate the need for virulence factors such as capsules, flagella, pilli, or toxins to circumvent mucosal barriers. Instead, the pathogen uses host macrophages, where it establishes intracellular niches, for its migration into the lung parenchyma and other tissues and for the induction of long-lived latency in granulomas. Finally, at the end of the infection cycle Mtb induces necrotic cell death of macrophages to escape to extracellular milieu and instructs a strong inflammatory response required for progression from latency to disease and transmission. Common to all these events is ESAT-6, one of the major virulence factors secreted by the pathogen. This review highlights the recent advances in understanding the role of ESAT-6 in hijacking macrophage function to establish a successful infection and transmission and its use as a target for the development of diagnostic tools, and vaccines.
REVIEW | doi:10.20944/preprints202303.0112.v1
Subject: Biology And Life Sciences, Virology Keywords: Viruses; Escherichia coli; Klebsiella aerogenes; Candida utilis; Gibbs energy of biosynthesis; Bi-osynthesis reaction; Enthalpy; Entropy; Pathogen-host interaction
Online: 6 March 2023 (15:47:22 CET)
Pathogen-host interaction (virus-host, bacteria-host and fungi-host) is analyzed from the perspective of biothermodynamics. A mechanistic model of pathogen-host interactions, which was earlier applied to virus-host interactions, was applied for the first time to bacteria-host and fungi-host interactions. Through a mechanistic model suggested in this research, it is possible to explain the phenomenon of tropism of microorganisms to develop infections in certain tissues. Gibbs energy of biosynthesis represents the driving force for growth of bacteria inside host organisms. A growing bacterial colony represents a thermodynamic system, while the host organism is its surroundings. The permissiveness coefficient determines the possibility of growth of bacteria in an appropriate environment (tissue).
REVIEW | doi:10.20944/preprints202011.0156.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: Bacterial detection; Biosensors; Clinical pathogen; COVID-19; Electrospun nanofibers; Nano-biosensors; Point-of-care; SARS-CoV-2; Viral detection.
Online: 3 November 2020 (14:15:34 CET)
Biosensors are measurement devices that can sense several biomolecules, and are widely used for the detection of relevant clinical pathogens such as bacteria and viruses, showing outstanding results. Because of the latent existing risk of facing another pandemic like the one we are living due to COVID-19, researchers are constantly looking forward to developing new technologies for diagnosis and treatment of infections caused by different bacteria and viruses. Regarding that, nanotechnology has improved biosensors design and performance through the development of materials and nanoparticles that enhance their affinity, selectivity, and efficacy in detecting these pathogens, such as employing nanoparticles, graphene quantum dots, and electrospun nanofibers. Therefore, this work aims to present a comprehensive review that exposes how biosensors work in terms of bacterial and viral detection, and the nanotechnological features that are contributing to achieving a faster yet still efficient COVID-19 diagnosis at the point-of-care.