Background. Escherichia coli commonly causes catheter-related bloodstream infection (C-RBSI) in specific populations. The differential time to positivity (DTTP) technique is the recommended conservative procedure for diagnosing C-RBSIs. Methods. We conducted a retrospective study of episodes in which E. coli was isolated from catheter lumens obtained using the DTTP technique. We analysed microbiological and clinical data based on the DTTP technique as either catheter colonization, C-RBSI, or non-C-RBSI. Results. We included 89 catheter blood cultures classified as follows: catheter colonization, 33.7%; C-RSBI, 9.0%; and non-C-RBSI, 57,3%. Catheter withdrawal was 15.7% without positive catheter-tip cultures. We found no statistically significant differences in catheter type, antibiotic treatment, or clinical outcome among groups, except for the frequency of catheter lock therapy or in the frequency of successful treatment. Mortality was associated with C-RBSI in only 1 patient. Conclusion. E. coli bacteremia diagnosed by the DTTP technique was non-catheter related in most patients. As the majority of the catheters were retained, E. coli bacteremia could not be microbiologically confirmed or ruled out as catheter related by catheter-tip culture. Future studies are needed to assess the profitability of the DTTP technique for diagnosing E. coli C-RBSIs..

Enterococcus faecalis is a growing cause of nosocomial and antibiotic-resistant infections. Treating drug-resistant E. faecalis requires novel approaches. The use of bacteriophages (phages) against multidrug-resistant (MDR) bacteria has recently garnered global attention. Biofilms play a vital role in E. faecalis pathogenesis as they enhance antibiotic resistance. Phages eliminate biofilms by producing lytic enzymes, including depolymerases. In this study, Enterococcus phage vB_Efs8_KEN04 (ФKEN04), isolated from a sewage treatment plant in Nairobi, Kenya, was tested against clinical strains of MDR Enterococcus faecalis. This phage had a broad host range against 100% (26/26) of MDR E. faecalis clinical isolates and cross-species activity against Enterococcus faecium. It was able to withstand acidic and alkaline conditions, from pH 3 to 11, as well as temperatures between -80ᵒC and 37ᵒC. It could inhibit and disrupt the biofilms of MDR E. faecalis. Its linear double-stranded DNA genome of 142,402 bp contains 238 coding sequences with a G+C content and coding gene density of 36.01% and 91.46%, respectively. Genomic analyses showed that ФKEN04 belongs to the genus Kochikohdavirus in the family Herelleviridae. It lacked antimicrobial resistance, virulence, and lysogeny genes, and its stability, broad host range, and cross-species lysis indicate strong potential for the treatment of Enterococcus infections.

This study was performed to evaluate the efficacy of nicotinic acid against Streptococcus pneumoniae biofilm. The experimental results indicate that S. pneumoniae forms biofilms, particularly at the liquid-air interface, as evidenced by the pellicle assay. Nicotinic acid demonstrated significant inhibition of S. pneumoniae biofilm formation at 6 h and 18 h, with higher concentrations leading to lower biofilm biomass, suggesting a concentration-dependent response. However, minimal biofilm inhibition was observed at 12 h. Treatment with nicotinic acid induced FTIR spectral changes in protein biomolecules of S. pneumoniae biofilm at 6 h and 18 h, evidenced by alterations in spectral peaks at 750 cm-1, 906 cm-1, 1540 cm-1, 1548 cm-1, and 1644 cm-1. Notably, no FTIR spectral changes were detected in 12 h S. pneumoniae biofilm following exposure to nicotinic acid. These findings suggest that nicotinic acid inhibits biofilm formation in a time and concentration-dependent manner, possibly by altering the structure of protein biomolecules within the biofilm.

The occurrence and ability of Salmonella typhimurium to withstand the effects of various antibiotics has been extensively recorded. This highlights the necessity for alternative methods to combat Salmonella infections. The current investigation aimed to ascertain the impact of benzoic acid on the extent of surface coverage and biomass of S. typhimurium biofilm after 48 and 72 hours. The findings indicated that all the different doses of benzoic acid (ranging from 3.125% to 50%) resulted in a decrease in the extent of biofilm surface coverage. Benzoic acid exhibited a substantial inhibitory effect on the biofilm biomass at all concentrations. Higher concentrations of benzoic acid led to a decrease in biofilm biomass, suggesting a concentration-dependent response. This finding implies that benzoic acid is effective in managing Salmonella infections.

: Since the COVID-19 pandemic, people have become aware that materials (products) can transmit infection and have begun to focus on questions such as how bacteria and germs, the sources of in-fection, maintain their infectivity on material surfaces, and the extent to which materials can or cannot prevent this. and to what extent materials can and cannot prevent it. The SIAA, a non-profit organization of many Japanese companies, had created an entirely separate interna-tional standard for materials' antibacterial, antiviral, and antibiofilm properties (products). The authors have studied the academic basis for the operation of the standards and were deeply in-volved as researchers in establishing one of the standards. This paper describes the interna-tional standards and some representative examples of the authors' actual use of these standards and explains the current status and future problems.

Objective Rhinosinusitis is a chronic condition characterized by frequent episodes of recurrence; its main treatment is pharmacological and this therapy should be continued for a long time until stabilization of the problem. Some patients, however, often must resort to targeted therapies for disease recurrences, which is why targeted preventive treatments are sought. Methods In the study performed, Pistacia lentiscus oil was used. Two groups of patients were studied with endoscopy, SNOT 22 and Nasal Cytology to evaluate nasal cellularity and ciliar motility. Results Pistacia lentiscus oil has the ability to reduce mucosal inflammation, by destroying and preventing the formation of biofilm. Conclusion The study showed that daily administration of Pistacia lentiscus oil significantly reduced the presence of biofilm. Moreover, continuous use of a lentiscus oil wash significantly reduced patients’ symptoms and improved their quality of life according to the Snot 22 questionnaire.

Salmonella typhimurium is the predominant serovar identified in cases of salmonellosis. It is recognised for adhering to various surfaces and creating biofilm, leading to several foodborne outbreaks and antibiotic resistance. Actinomycetes are thought to possess a wide array of antibacterial characteristics that can combat different diseases. Currently, it is unclear whether it has antibiofilm properties against S. typhimurium. This study aimed to assess the antibiofilm efficacy of actinomycetes extracts against S. typhimurium ATCC 14028 by the Crystal Violet assay. Four actinomycetes isolates, EAS5, EAS7, EAA141, and EAA11, were obtained from BRIS soil in Terengganu. The actinomycetes isolates were extracted using ethyl acetate (EA). S. typhimurium was exposed to extracts for 6, 12, and 18 hours. The results showed that all EA extracts effectively prevented the S. typhimurium biofilm at 12 and 18 hours. EAAA11 was the most effective against the 12-hour biofilm, whereas EAS5 was the most effective against the 18-hour biofilm among these extracts. In conclusion, actinomycetes isolated from the BRIS soil in Terengganu show potential for controlling Salmonella infection.

Hybrid materials are a recent addition in the field of Restorative Dentistry for computer-assisted design/ computer-assisted manufacturing (CAD/CAM) indirect restorations. The long–term clinical success of modern dental restorative materials follows a multifactorial pattern. Among the characteristics, affecting the longevity of a restoration, mechanical properties and physicο – chemical interactions are of utmost importance. While numerous researchers constantly evaluate the mechanical properties, the biological background of resin–based CAD/CAM biomaterials is scarcely investigated and, therefore, less described in the literature. This review aims to analyze the biofilm formation on the surfaces of novel hybrid, resin–based CAD/CAM materials and evaluate the methodological protocols followed to assess microbial growth. It is demonstrated that the surface structure, the composition and the finishing and polishing procedures on the surface of a dental restorative material influence the initial bacterial adhesion; however most studies focus on in vitro protocols, whereas in vivo and/or in situ research of microbiomics in CAD/CAM restorative materials is lacking, obstructing in that manner the accurate understanding of the bioadhesion phenomenon in the oral cavity.

Candida (C.) infections represent a serious health risk for people affected by inflammatory bowel disease. An important fungal virulence factor is the capacity to form biofilms on the colonized surface of the host. This research study aimed to determine the effect of C. tropicalis and C. albicans co-infection on dextran sodium sulfate (DSS)-induced colitis in mice. Colitis severity was evaluated using histology and colonoscopy. Mice were mono-inoculated with C. albicans, C. tropicalis or co-challenged with both species. Mice were administered 3% DSS to induce acute colitis. Biofilm activity was assessed using (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl] 2H-tetrazoliumhydroxide (XTT) assay. Abundance of C. albicans in the colon tissues was assessed by immunohistochemistry. Co-challenged mice showed decreased colitis severity compared to mono-inoculated mice. The XTT assay demonstrated a marked decrease of C. albicans biofilm production in a C. albicans culture incubated with C. tropicalis supernatant. Immunohistochemical staining showed that C. albicans was more abundant in the mucosa of C. albicans mono-inoculated mice compared to the co-inoculated group. These data indicate an antagonistic microbial interaction between the two Candida species, where C. tropicalis may produce molecules capable of limiting the ability of C. albicans to adhere to the host intestinal surface leading to a reduction in biofilm formation.

Background: Mycobacterium avium complex includes the commonest nontuberculous mycobacteria associated with human infections. These infections have been associated with the production of biofilms in many cases, but there are only a few studies about biofilms produced by the species included in this group. Methods: Three collection strains (M. avium ATCC25291, M. intracellulare ATCC13950, and M. chimaera DSM756), three clinically significant strains (647, 657, and 655), and three clinically nonsignificant ones (717, 505, and 575) of each species were included. The clinical significance of the clinical isolates was established according to the internationally accepted criteria. Biofilm ultrastructure was studied by Confocal-Laser Scanning Microscopy using Backlight Live dead and Red Nile stains. Viability, covered surface, height and relative autofluorescence were measured in several images/strain. The effect of clarithromycin was studied the technique described by Muñoz-Egea et al with modifications regarding incubation time. The study included clarithromycin in the culture medium at a concentration achievable in the lungs (11.3 mg/L), using one row of wells as the control without antibiotic. Bacterial viability inside the biofilm is expressed as a percentage of viable cells. The differences between the different parameters of biofilm ultrastructure were analysed using Kruskal-Wallis test. The correlation between bacterial viability in the biofilm and treatment time was evaluated using Spearman's rank correlation coefficient (ρ). Results: The strains showed differences between them with all the studied parameters, but neither a species-specific pattern nor a clinical significance-specific patter were detected. For the effect of clarithromycin, the viability of the bacteria contained in the biofilm was inversely proportional to the exposure time of the biofilm (ρ > -0.3; p-value < 0.05), excluding two M. chimaera strains (M. chimaera DSM756 and 575), which showed a weak positive correlation with treatment time (0.2 < ρ < 0.39; p-value < 0.05). Curiously, despite a clarithromycin treatment of 216 hours, the percentage of biofilm viability of the strains evaluated here was not less than 40% at best (M. avium 717). Conclusions: All the M. avium complex studied strains are able to form biofilm in vitro, but ultrastructural characteristics between them suggest that these are strain-specific characteristics unrelated with neither with the species nor with the clinical significance. The clarithromycin effect on MAC species is biofilm age/time of treatment-dependent and appears to be strain-specific while being independent of the clinical significance of the strain.

The purpose of the present study was to investigate anti-staphylococcal activity of liposomal daptomycin, against four biofilm-producing S. aureus and S. epidermidis clinical strains, three of which are methicillin resistant. Neutral and negatively charged Daptomycin-loaded liposomes were prepared by three methods thin film hydration (TFH), DRV and microfluidic mixing (MM), and characterized for drug encapsulation (EE%), size distribution, zeta-potential, vesicle stability, drug release and drug integrity. Interestingly, whilst drug loading in THF and DRV nanosized (by extrusion) vesicles was around 30-35, very low loading (~4%) was possible in MM vesicles, requiring further explanatory investigations. Liposomal encapsulation protected daptomycin from degradation and preserve its bioactivity. Quantitative microtiter plate (crystal violet, CV), methylthiazoltetrazolium (MTT), and growth curve (GC) assays evaluated antimicrobial activity of neutral and negative charge daptomycin-liposomes towards planktonic bacteria and biofilms. Neutral liposomes exhibited dramatically enhanced inhibition of bacteria growth (compared to free drug) for all species studied, while negative charged liposomes were totally inactive. Biofilm prevention and treatment studies revealed high antibiofilm activity of liposomal daptomycin. Neutral liposomes were more active for prevention and negative charge ones for treating established biofilms. Planktonic bacteria as well as matured biofilms of low daptomycin susceptible MRSE and MRSA strains were almost completely eradicated by liposomal-daptomycin indicating the need for their further exploration as antimicrobial therapeutics.

Pseudomonas aeruginosa is an opportunistic pathogen that poses a significant threat to individuals with chronic respiratory ailments, such as cystic fibrosis (CF). The pathogen is highly prevalent in CF individuals and is responsible for chronic infection, resulting in severe tissue damage and poor patient outcome. However, early detection and immediate treatment are critical to prevent bacterial persistence and establishment of chronic infection. Presently, antibiotics including aminoglycosides, beta-lactams, polymyxins, and fluoroquinolones along with anti-inflammatory medications are being used to treat P. aeruginosa infections in CF patients. However, prolonged antibiotic administration has led to the emergence of widespread multidrug resistance in P. aeruginosa (CF isolates), contributing to antimicrobial resistance (AMR) and failure of antimicrobial therapies. Thus, exploring viable alternatives such as antivirulence therapeutics can be vital towards managing pseudomonal infections in CF patients and mitigating the risk of AMR. In this direction, antivirulence strategies achieving targeted inhibition of bacterial virulence pathways/factors, including quorum sensing, efflux pumps, lectins, and iron chelators, have been widely explored against CF isolates of P. aeruginosa. Simultaneously, there have been discussions about the sufficiency of in vitro findings and their successful translation in pulmonary infection models (in vivo) for the clinical implementation of antivirulence therapies hence, this review article presents a bird’s eye view on the pulmonary infections involving P. aeruginosa in CF patients by laying emphasis on factors contributing to bacterial colonization, persistence, and disease progression along with the current line of therapeutics against P. aeruginosa in CF while underscoring the limitation of antimicrobial approaches. We further collate scientific literature and comprehensively discuss the various antivirulence strategies that have been successfully tested against P. aeruginosa isolates from CF patients. This could pave the way towards a paradigm shift towards clinical therapy of pseudomonal infections in CF and can potentially override conventional antimicrobial treatments.

This study explores the pivotal biofilm life cycle, essential for comprehending intricate processes in biofilm formation and dispersal. With profound implications for medicine, environmental science, and industrial applications, the life cycle involves initial attachment, irreversible attachment, maturation, and dispersion. Employing bibliographic analysis, the paper unravels critical aspects, unveiling key keywords, prominent research countries/regions, and significant research organizations. This comprehensive approach provides insights into the current biofilm research landscape, identifying gaps for future exploration. Biofilm's influence extends to medical conditions, environmental ecosystems, and industrial challenges, accentuating the urgency of understanding its life cycle. The study also delves into global research distribution and influential organizations, guiding collaborative efforts. As a forward-looking initiative, it proposes future research opportunities, aiming to steer advancements and address challenges in biofilm science. Ultimately, this analysis contributes to the ongoing progress of biofilm research, fostering interdisciplinary collaboration and inspiring future initiatives.

Methicillin-resistant Staphylococcus aureus (MRSA) infections, in particular biofilm-organized bacteria, remain a clinical challenge and a serious health problem. Rifabutin (RFB), an antibiotic of the rifamycins class, has shown in previous work excellent anti-staphylococcal activity. Here, we proposed to load RFB in liposomes aiming to promote the accumulation of RFB at infected sites and consequently enhancing the therapeutic potency. Two clinical isolates of MRSA, MRSA-C1 and MRSA-C2, were used to test the developed formulations, as well as the positive control, vancomycin (VCM). RFB in free and liposomal forms displayed high antibacterial activity, with minimal inhibitory concentrations (MIC) ranging from 0.009-0.013 μg/mL and MBIC50 values ranging from 0.008-0.012 μg/mL, in planktonic and biofilm bacteria, respectively. Confocal microscopy studies demonstrated the rapid internalization of unloaded and RFB-loaded liposomes in the bacterial biofilm matrix. In murine models of systemic MRSA-C1 infection, Balb/c mice were treated with RFB formulations and VCM at 20 and 40 mg/kg of body weight, respectively. Obtained data proved the superior therapeutic effectiveness of RFB formulations compared to Control and VCM groups even using a two-fold lower therapeutic dose as demonstrated by significantly reduced bacterial burden and growth index values in major organs. In addition, RFB formulations were the only formulations associated with 100% survival. Globally, this study emphasizes the potential of RFB nanoformulations as an effective and safe approach against MRSA infections.

This study aimed to evaluate the impact of Candida albicans on subgingival biofilm formation on dental implant surfaces. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to compare biofilm structure and microbial biomass in the presence and absence of the fungus after periods of 24, 48, and 72 h. Quantitative polymerase chain reaction (qPCR) was used to quantify the number of viable and total micro-organisms for each of the biofilm-forming strains. A general linear model was applied to compare CLSM and qPCR results between control and test conditions. The biofilm developed with C. albicans at 72 h had a higher bacterial biomass, with a significantly higher cell viability (p &lt; 0.05). After both 48 and 72 h of incubation, in the presence of C. albicans, there was a significant increase in counts of Fusobacterium nucleatum and Porphyromonas gingivalis and in the cell viability of Streptococcus oralis, Aggregatibacter actinomycetemcomitans, F. nucleatum, and P. gingivalis. Using a dynamic in vitro multispecies biofilm model, C. albicans exacerbated the development of the biofilm grown on dental implant surfaces, significantly increasing the number and cell viability of periodontal bacteria.

Micro nano bubbles (MNBs) can generate ·OH in situ, which provides a new idea for the safe and efficient removal of pollutants in water supply systems. However, the difficulty in obtaining stable MNBs causes the low efficiency of ·OH generation, which makes the inability to guarantee the removal efficiency of pollutants. This paper reviews the application research of MNBs technology in water security from three aspects: the generation process of MNBs in water, the generation rule of ·OH during MNBs collapse, and the control mechanism of MNBs on pollutants and biofilms. We found that MNBs generation methods are divided into chemical and mechanical (about 10 kinds) categories, and the instability of bubble size restricts the application of MNBs technology. The generation of ·OH by MNBs is affected by pH, gas source, bubble size, temperature, external stimulation. And pH and external stimulus have more influence on ·OH generation in situ than other factors. Adjusting pH to alkaline or acidic conditions and selecting ozone or oxygen as the gas source can promote the ·OH generation. MNBs’ collapse also releases a large amount of energy, which the temperature and pressure can reach 3000K and 5Gpa respectively, making it efficient to remove ≈90 % of pollutants (i.e., trichloroethylene, benzene, and chlorobenzene). The biofilm can also be removed by physical, chemical, and thermal effect. MNBs technology also has great application potential in drinking water, which can be applied to improve water quality, optimize household water purifiers, and enhance the taste of bottled water. Under the premise of safety, let people of different ages taste, finding that compared with ordinary drinking water, 85.7 % of people think MNBs water is softer, 73.3 % of people think MNBs water is sweeter. This further proves that MNBs water has a great prospect in the drinking water application. This review provides innovative theoretical support for solving the problem of drinking water safety.

Boswellia trees are the source of frankincense, which can be found throughout the Middle East and parts of Africa and Asia. Boswellia serrata extract has been shown to have anti-cancer, anti-inflammatory, and anti-microbial effects. Periodontitis is an oral chronic inflammatory disease that affects nearly half of the US population. We investigated the antimicrobial effects of B. serrata extract on two oral pathogens associated with periodontitis. Using the minimum inhibitory concentration and crystal violet staining methods, we demonstrated that Porphyromonas gingivalis growth and biofilm formation were impaired by treatment with B. serrata extracts. However, there were no significant effects on Fusobacterium nucleatum growth and biofilm formation. Using colony-forming units quantification and microscopy techniques, we also showed that concentrations of B. serrata that were not toxic for host cells decreased intracellular P. gingivalis infection in human gingival epithelial cells. Our results show antimicrobial activity of a natural product extracted from Boswellia trees (B. serrata) against periodontopathogens. Thus, B. serrata has the therapeutic potential for preventing and/or treating periodontal diseases. Future studies will identify molecular components of B. serrata extracts responsible for the beneficial effects.

Breast cancer is the most common cancer in women globally, often necessitating mastectomy and subsequent breast reconstruction. Silicone mammary implants (SMIs) play a pivotal role in breast reconstruction, yet their interaction with the host immune system and microbiome remains poorly understood. This study investigates the impact of SMI surface topography on host antimicrobial responses, wound proteome dynamics, and microbial colonization. Biological samples were col-lected from ten human patients undergoing breast reconstruction with SMIs. Mass spectrometry profiles were analyzed for acute and chronic wound proteomes, revealing a nuanced interplay between topography and antimicrobial respondseproteins. 16S rRNA sequencing assessed mi-crobiome dynamics, unveiling topography-specific variations in microbial composition. Surface topography alterations influenced wound proteome composition. Microbiome analysis revealed heightened diversity around rougher SMIs, emphasizing topography-dependent microbial inva-sion. In vitro experiments confirmed staphylococcal adhesion, growth, and biofilm formation on SMI surfaces, with increased texture correlating positively with bacterial colonization. This comprehensive investigation highlights the intricate interplay between SMI topography, wound proteome dynamics, and microbial transmission. The findings contribute to understanding host-microbe interactions on SMI surfaces, essential for optimizing clinical applications and minimizing complications in breast reconstruction.

This paper explores the multifaceted impact of biofilms, bacterial communities enveloped in extracellular polymeric substance (EPS). Biofilms play a dual role, acting as environmental champions and health threats. They interact with heavy metals, either causing pollution or aiding environmental remediation. Beneficial biofilms generate electricity and repair concrete cracks, offering sustainable solutions. Conversely, they contribute to infections, posing health risks. The study emphasizes the need for in-depth research, utilizing bibliographic methods to analyze global biofilm research. By identifying keywords, core countries, and pivotal organizations, the paper informs future investigations, offering insights into biofilm research evolution and practical applications.

This work aimed to identify chemical compounds of Cinnamomum burmannii leaf essential oil (CBLEO) and to unravel antibacterial mechanism of CBLEO at molecular level for developing antimicrobial. CBLEO had 37 volatile profiling with abundant borneol (28.40 %), and showed good potential to control foodborne pathogens, of which Staphylococcus aureus had the greatest inhibition zone diameter (28.72 nm) with the lowest values of minimum inhibitory concentration (1.0 μg/mL) and bactericidal concentration (2.0 μg/mL). To unravel antibacterial action of CBLEO on S. aureus, a dynamic exploration of antibacterial growth, material leakage, ROS formation, protein oxidation, cell morphology and interaction with genome DNA were conducted on S. aureus exposed to CBLEO at different doses (1/2-2×MIC) and times (0-24 h), indicating that CBLEO acts as inducer for ROS production and oxidative stress of S. aureus. To highlight antibacterial action of CBLEO on S. aureus at molecular level, a comparative association of ROS accumulation with some key virulence-related gene (sigB/agrA/sarA/icaA/cidA/rsbU) transcription, protease production and biofilm formation in S. aureus subjected to CBLEO at different levels and times, revealing that CBLEO-induced oxidative stress caused transcript suppression of virulence regulators (RsbU and SigB) and its targeted genes, causing protease level increase destined for biofilm formation and growth inhibition of S. aureus, which may be as key bactericidal action. Our findings provide valuable information for studying the antibacterial mechanism of essential oil against pathogens.

Bacteria of the genus Staphylococcus are a significant a challenge for medicine, as many species are resistant to multiple antibiotics and even to all of the antibiotics used. One of the approaches to develop new therapeutics to treat staphylococcal infections is the use of bacteriophages specif-ic to these bacteria or lysins of such bacteriophages capable to hydrolyze the cell walls of these bacteria. In this study, a new bacteriophage St_134 specific to Staphylococcus epedermidis was de-scribed. This small podophage belonging to the Andhravirus genus showed relatively wide host range and was able to infect more than 60 strain of Staphylococcus spp., including a clinical strain from the Staphylococcus aureus complex. Two genes encoding different phage lysins were identi-fied in the Ste134 genome. Both lysins LysSte134_1 and LysSte134_2 were produced in Escherichia coli cells. Endolysin LysSte134_1 was demonstrated catalytic activity against a wide panel of staphylococcal peptidoglycans (4 species, 6 strains), was active against S. aureus and S. epidermidis planktonic cultures and destroyed biofilms formed by clinical strains of S. aureus and S. epider-midis.

This paper explores the intricate world of microbial life, focusing on biofilm as a dynamic consortium of bacteria forming complex networks within a self-produced matrix of extracellular polymeric substances (EPS). Analogous to a bacterial house, these structures provide both shelter and support, playing a pivotal role in the microbial realm with dual effects on human and environmental contexts. Biofilm's significance extends beyond its microcosmic architecture, positively contributing to heavy metal removal, electricity generation through microbial fuel cells, and structural remediation, while also posing threats with detrimental formations implicated in conditions from lung to urinary tract infections. Control of biofilm becomes imperative to unlock its positive attributes and mitigate potential negatives, serving as a cornerstone for environmental remediation, sustainable energy, and infrastructure maintenance. Employing a comprehensive bibliographic approach, this study identifies keywords, countries, and organizations influencing biofilm research, proposing innovative avenues like machine learning for future exploration. The aim is not only to contribute to existing knowledge but to pioneer cutting-edge strategies for biofilm optimization and challenge mitigation, shaping its trajectory towards sustainable applications across diverse fields.

This study aimed to analyse the effect of chlorhexidine digluconate (CHX DG) mouthwash on the adhesion of oral bacteria to orthodontic appliances. The interactions of four bacteria (S. mutans, A. actinomycetemcomitans, S. oralis, and V. parvula) with two alloys (stainless steel [SS] and nickel-titanium [NiTi]) and three CHX DG solutions (commercial products Curasept and Perio Plus, and pure CHX DG, all with 0.12% active substance) were tested. The adhesive effect on the orthodontic wires was evaluated after 24 h for S. oralis and after 72 h for the other bacteria. The minimum bactericidal concentration of the solution for each bacterial strain was determined using the dilution method to test the antibacterial action. Salivary-pretreated orthodontic arch wires were exposed to minimal bactericidal concentrations of solution and bacteria. Commercial antiseptic products, especially Perio Plus, showed better inhibition of bacterial adhesion to both alloys than pure CHX DG solution (p&lt;0.05). A. actinomycetemcomitans was most inhibited in the adhesion of all bacteria by the CHX DG products. Greater inhibition of streptococci adherence was observed on SS, while A. actinomycetemcomitans on NiTi. Inhibition of V. parvula was product dependent. In conclusion bacterial adhesion depends on the alloys, antiseptic products, and the bacteria. CHX DG is effective at inhibiting bacterial adhesion to orthodontic elements and is recommended for the chemical control of biofilms during orthodontic treatment with fixed appliances.

Ocular pathologies present significant challenges in achieving effective therapeutic re-sults due to various anatomical and physiological barriers. Natural products, such as flavonoids, alone or in association with allopathic drugs, present many therapeutical actions, including anti-cancer, anti-inflammatory, and antibacterial action. However, their clinical employment is chal-lenging for scientists due to their low water solubility. In this study, we designed a liquid formu-lation based on rutin/sulfobutylether-β-cyclodextrin (RTN/SBE-β-CD) inclusion complex for treating ocular infections. The correct stoichiometry and the accurate binding constant were de-termined by employing the SupraFit software on the Uv-vis titration experiment. A deep physical-chemical characterization of the RTN/SBE-β-CD inclusion complex was also performed; it con-firmed the predominant formation of a stable complex (Kc, 9660 M−1) in a 1:1 molar ratio, with high water solubility of 20 times (2.5 mg/mL) higher than the free molecule (0.125 mg/mL), per-mitting the dissolution of the solid complex within 30 min. NMR studies revealed the involve-ment of the bicyclic flavonoid moiety in the complexation, which was also confirmed by molecu-lar modeling studies. In vitro, the antibacterial and antibiofilm activity of the formulation was assayed against Staphylococcus aureus and Pseudomonas aeruginosa strains demonstrating a sig-nificant activity of the formulation to the free components.

The reproductive health of women is governed by an optimal balance between the host-microbiota interaction. Depletion in the beneficial vaginal microflora caused by depletion of Lactobacillus species and increased proliferation of pathogens results in gynecological infections. Among women of reproductive age, vaginal infections are increasingly prevalent. Attaining therapeutic efficacy using conventional formulations remains a challenge as vaginal fluids quickly remove or dilute the therapeutic formulations. Hydrogels have been widely exploited for targeted delivery of therapeutics directly into the vaginal mucus. With careful choice of polymers (natural, synthetic or semi-synthetic) hydrogels with specific properties such as stimuli-responsiveness, antimicrobial, and muco-adhesiveness can be tailored for higher therapeutic efficacy. In this review, the advnances in hydrogel strategies for the treatment of vaginal infections is presented with emphasis on the types and properties that play a significant role in vaginal drug delivery systems.

The bacterial adhesion to food contact surfaces is a threat to human health, as these surfaces can serve as a reservoir of pathogenic bacteria. Escherichia coli is a biofilm-forming bacterium involved in surface contamination. Despite the application of disinfection protocols, contamination continues to occur. Hence, new effective and sustainable approaches are needed. Bacteriophages (or simply phages), viruses that only infect bacteria, have proven to be effective in reducing biofilms. Here, phage phT4A was applied to prevent and reduce E. coli biofilm on plastic and stainless steel. The assays were performed in Tryptic Soy Broth (TSB), at 25 °C. The biofilm formation capacity of phage-resistant and sensitive bacteria, after treatment, was also evaluated. Maximum reductions on E. coli biofilm of 5.5 log colony forming units (CFU)/cm2 (after 6 h) and 4.1 log CFU/cm2 (after 9 h), on plastic and stainless steel, respectively, were observed. In the prevention assays, phage prevented biofilm formation in 3.2 log CFU/cm2, after 12 h. Although the emergence of phage-resistant bacteria has been observed during phage treatment, a lower biofilm formation capacity was observed by phage-resistant bacteria comparatively to phage-sensitive bacteria. Overall, phages have shown to be a promising approach to decontaminate food handling surfaces.

Biofilm serves as the residence for bacteria, wherein bacteria attach to surfaces and produce extracellular polymeric substances, including proteins, polysaccharides, and extracellular DNA. In recent years, biofilm reactors have gained increasing significance, playing a crucial role, for instance, in immobilizing heavy metals from waterways. This paper employs a bibliographic study to analyze the most important keywords and organizations in the field of biofilm reactors, identifying recent significant papers. Additionally, the paper discusses the opportunities for the future development of biofilm reactors. Through this study, a better understanding of key factors in biofilm reactor research is achieved, providing valuable guidance for future studies and applications in this field.

Helicobacter pylori infections are still an urgent and hot topic. This is related to the involvement of H. pylori in human diseases (including gastric diseases, gastric adenocarcinoma, mucosa-associated lymphoid tissue lymphoma, and diabetes), the number of which is constantly increasing. At the same time, agents effective against these bacteria are decreasing due to spreading resistance. Our research focused on extracts of the Rubus genus, commonly present in Central and Eastern Europe and very useful in folk medicine. Results have shown that the extract from Rubus idaeus 'Willamette' shoots, and the extract from R. idaeus 'Poranna Rosa' fruits and R. idaeus 'Laszka' R. occidentalis Litacz' fruits prevent the formation of biofilm by H. pylori on intravenous infusions (they reduce living cells, which was detected using triphenyl tetrazolium chloride (TTC) as a dye) at concentrations of 6.65 and 16.65 mg/mL, respectively. However, the living bacteria in the formed biofilm are affected by the extract from the shoots of R. idaeus 'Willamette' and the fruit of R. idaeus 'Poranna Rosa' at a concentration of 16.65 mg/ml, and the remaining extracts at a concentration of 33.3 mg/ml. The results of the study of interactions of extracts from Rubus sp. and the 2 antibiotics against H. pylori planktonic bacteria showed doxycycline synergism with all tested extracts, but only the extract of R. occidentalis 'Litacz' with levofloxacin. The remaining tested extracts showed indifference with levofloxacin. However, studies on the interaction between antibiotics and extracts of R. idaeus 'Willamette' shoot showed synergy with doxycycline and levofloxacin, additivity with amoxicillin and clarithromycin, and indifference with metronidazole. The tests were carried out on fragments of intravenous infusions with TTC as a dye. The tested extracts may be elements of broadly understood anti-H. pylori therapy.

Coagulase-Negative Staphylococci (CoNS) are commensal on human body surfaces and for years, they were not considered a cause of bloodstream infection and were often regardered as contamination. However, the association of CoNS with nosocomial infection is increasingly recognized. The insertion of cannulas and intravascular catheters represents the first source of CoNS entry into the bloodstream, causing bacteremia and sepsis. They owe their pathogenic power to their ability to produce biofilms on surfaces, such as medical devices. In this study, we evaluate the adhesive capacity of CoNS isolated from blood cultures by comparing spectrophotometric phenotypic assay with genotypic analysis based on the evidence of the ica operon. We retrospectively reviewed the database of CoNS isolated from blood cultures, that were considered to be responsible for 361 bloodstream infections. Among them, we selected 89 ones who had full records. Our data show that S. epidermidis was the predominant species isolated, and with greater adhesive capacities, especially those with the complete operon. Knowing the adhesive capabilities of a microorganism responsible for sepsis can be useful in implementing appropriate corrective and preventive measures, as conventional antibiotic therapy cannot effectively eradicate biofilms.

Biofilm-related infections play a significant role in the development and persistence of ventilator-associated pneumonia. Pseudomonas aeruginosa frequently causes biofilm-related infections associated with ventilator tubing. Glucosamine gold nanoparticles (AuNPs) may exhibit antibiofilm properties; however, more studies, including combinatorial therapy with antibiotics, are needed to explore their potential applications in clinical settings. This study aimed to investigate the biofilm inhibition properties of glucosamine AuNPs in combination with meropenem against Pseudomonas aeruginosa ATCC 9027 on the endotracheal tube. A biofilm inhibition assay of glucosamine AuNPs at 0.02 mg/ml, both singly and in combination with meropenem at 1 mg/ml, was carried out against Pseudomonas aeruginosa ATCC 9027 on an endotracheal tube using the tissue culture plate method. Scanning electron microscopy was performed for visualization. Glucosamine AuNPs at 0.02 mg/ml combined with meropenem at 1 mg/ml showed greater biofilm inhibition (72%) than glucosamine nanoparticles at 0.02 mg/ml alone (26%) on the endotracheal tube (p=0.001). The scanning electron microscopic visualization revealed that the untreated Pseudomonas aeruginosa biofilm was denser than the glucosamine nanoparticles-treated biofilm either combined with meropenem or glucosamine nanoparticles alone. The combination of glucosamine AuNPs and meropenem may have the synergistic effect to inhibit biofilm production of Pseudomonas aeruginosa on the endotracheal tube in patient with mechanical ventilation. Conducting additional experiments to explore the impact of combining glucosamine-coated gold nanoparticles (AuNPs) with meropenem on the inhibition of biofilm production by clinical Pseudomonas aeruginosa isolates would be beneficial.

Washing machines are one of the tools that bring great convenience to people's daily lives. However, washing machines that have been used for a long time often develop issues such as odor and mold, which can pose health hazards to consumers. There exists a conspicuous gap in our understanding of the microorganisms that inhabit the inner workings of washing machines. In this study, samples were collected from 22 washing machines in Shanghai, China, including both water eluted from different parts of washing machines and biofilms. Quantitative qualitative analysis was performed using fluorescence PCR quantification and microbial communities were characterized by high throughput sequencing (HTS). It showed that the microbial communities in all samples were predominantly composed of bacteria, and they have a strong adhesion ability in the washing machine environment. HTS results showed that in the eluted water samples, the bacteria mainly included Pseudomonas, Enhydrobacter, Brevibacterium and Acinetobacter. On the contrary, in biofilm samples, Enhydrobacter and Brevibacterium were the predominant bacterial microorganisms. Correlation analysis results revealed that microbial colonies in washing machines were significantly correlated with years of use and the type of detergent used to clean the washing machine. As numerous pathogenic microorganisms can be observed in the results, effective preventive measures and future research are essential to mitigate these health problems and ensure the continued safe use of these household appliances.

The emergence of antimicrobial resistance remains one of the greatest public health concerns. Biofilm formation has been postulated as a mechanism of microbial pathogens to resist antimicrobial agents. Lactic Acid Bacteria (LAB) and their metabolites have been proposed to combat bacterial biofilms, due to their antimicrobial activity. In this vein, the aim of the present study was to investigate the biofilm removal potential of cell-free supernatant (CFS) of five wild-type Lacticaseibacillus rhamnosus LAB strains, isolated from Greek natural products, in comparison to the commercial available L. rhamnosus GG strain, formed by common foodborne pathogens (Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus). Biofilm removal activity of LAB was assessed on two-days mature biofilm using a microtiter plate-based procedure. Both non-neutralized and neutralized CFSs removed biofilms in a concentration-dependent manner. Biofilm removal activity of the non-neutralized CFSs was significantly higher compared to the neutralized CFSs, as expected, ranging 40 – 90% and 10 – 78%, respectively. Biofilm removal efficiency of L. rhamnosus OLXAL-3 was signifanctly higher among the wild-type L. rhamnosus strains tested (20 – 100% v/v). In conclusion, our results suggested the great potential of application of wild-type Lacticaseibacillus rhamnosus strains CFSs as effective natural agents against pathogenic bacterial biofilms.

Staphylococcus aureus is a causative agent of nosocomial infections and its antibiotic-resistant strains are concerning. Solutions are being explored to improve the treatment of these infections, including repositioning drugs such as statins and using nanoparticles with antimicrobial properties. This study aimed to evaluate the antimicrobial effects of simvastatin (SIM) and biologically synthesized silver nanoparticles (bio-AgNPs) in isolate form and in combination by assays of minimum inhibitory concentration (MIC), an in vitro biofilm model, and the association of antimicrobials against clinical strains of S. aureus. Bio-AgNPs showed a 53.8 ± 1.23-nm mean diameter and standard deviation, a 0.23 polydispersity index, and a −25.66 ± 2.19-mV mean potential and standard deviation. Transmission electron microscopy confirmed the formation of nanoparticles and the presence of Ag0 and AgCl. S. aureus strains were sensitive to bio-AgNPs and SIM, showing 31.88-187.5 and 74.66-149.32 μM concentrations, respectively. Our association assay showed 2.0 fractional inhibitory concentration indices (i.e., indifferent for clinical strains) and 0.32 values for the standard ATCC 29213 strain (synergy). Our biofilm inhibition assays with isolated SIM and bio-AgNPs showed decreased biofilm formation from 4× to ⅛ MICs, showing no synergism in association. These findings evince that simvastatin and bio-AgNPs at subinhibitory concentrations can serve as antimicrobial agents against S. aureus biofilm.

Biofilm matrix is akin to bacterial abodes, primarily composed of proteins, polysaccharides, extracellular DNA, and lipids, providing essential structural support to bacteria. While some biofilm matrix offers significant benefits, such as engineered biofilm reactors that assist in water pollutant removal, others pose risks to human health, potentially leading to conditions like lung infections. Realizing the potential of advantageous biofilm matrix and mitigating the harmful effects of detrimental ones necessitates a comprehensive and systematic exploration of this intricate domain. To facilitate this examination, our study leveraged a dataset of the 1000 most pivotal papers in the field and conducted an exhaustive bibliographic review. This paper serves as a valuable resource for understanding the current progress in biofilm matrix research and delving into vital avenues for future exploration in this dynamic field.

Biofilm-associated proteins (BAPs) are important in the development and resilience of biofilms, which are intricate populations of microbes protected by extracellular matrix. All members of the BAP family are known to possess common characteristics such as high molecular weight and a signal sequence for extracellular secretion. It has been shown that BAPs are directly linked to the pathogenicity of many bacteria. This mini review highlights several potential strategies to target BAPs for drug development.

Bioactive surface coatings have retained the attention of researchers and physicians due to their versatility and range of applications in orthopedics, particularly in infection prevention. Antibacterial metal nanoparticles (mNPs) are a promising therapeutic, with vast application opportunities on orthopedic implants. The current research aimed to construct a polyelectrolyte multilayer on a highly porous titanium implant using alternating thin film coatings of chitosan and alginate via the layer-by-layer (LbL) self-assembly technique, along with the incorporation of silver nanoparticles (AgNPs) or titanium dioxide nanoparticles (TiO2NPs), for antibacterial and osteoconductive activity. These mNPs were characterized for their physicochemical properties using quartz crystal microgravimetry with dissipation system, nanoparticle tracking analysis, scanning electron microscopy, and atomic force microscopy. Their cytotoxicity and osteogenic differentiation capabilities were assessed by AlamarBlue and alkaline phosphatase (ALP) activity assays, respectively. The antibiofilm efficacy of the mNPs tested against Staphylococcus aureus. The LbL polyelectrolyte coating was successfully applied to the porous titanium substrate. A dose-dependent relationship between nanoparticle concentration and ALP as well as antibacterial effects was observed. TiO2NP samples were also less cytotoxic than AgNP counterparts, although similarly antimicrobial. Together, these data serve as a proof-of-concept for a novel coating approach for orthopedic implants with antimicrobial and osteoconductive properties.

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.

Introduction: Silver nanoparticles have been extensively investigated in dental and orthopedic materials. However, the impregnation of bone graft with silver nanoparticles has been poorly investigated. Objectives: The aim of this study was to evaluate the in vitro antibiofilm activity of a bovine bone impregnated with silver nanoparticles. Methods: Bone scaffolds from cancellous bovine femur were used for the tests and impregnated with silver nanoparticles (50nm) by physical adsorption. Silver nitrate minimal inhibitory and bactericidal concentration were performed Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Enterococcus faecalis, Acinetobacter baumannii, and Escherichia coli. Disc diffusion tests for silver nanoparticles susceptibility and quantification of biofilm production on plate and bone with sessile cell count were also performed. Results: All pathogens were susceptible to silver with low minimal inhibitory concentration (0.25 – 4 mg/L). The scaffold impregnated with silver nanoparticles presented a significant reduction in the biofilm cells for all microorganisms with a reduction of more than 3 logs in colony forming units count. Conclusion: Bone scaffolds impregnated with silver nanoparticles can significantly reduce biofilm, and it can be a strategical material to be used as an implant for different approaches.

A biofilm is any syntrophic consortium of microorganisms in which cells adhere to one another and, in some cases, to a surface. These adherent cells become encased in a slimy extracellular matrix made up of extracellular polymeric substances (EPSs). Until now, the use of commercial disinfectants remains the main strategy to control biofilm-mediated problems. This mini review summarizes common antibiofilm mode of actions taken by disinfectants and how water channels in microbial biofilms contribute to disinfectant resistance.

Pulmonary infections with Mycobacterium avium occur in susceptible individuals following exposure to the bacterium in the environment, where it often persists in biofilms. Many methods have been used to generate biofilms of M. avium, and it is unknown whether different approaches generate similar structures and cell phenotypes. To make a parallel comparison of in vitro biofilm ultrastructure, extracellular matrix (ECM) composition, and drug susceptibility of biofilm resident bacteria, we used two published methods to generate M. avium biofilms: four week incubation in M63 medium or 24 hour exposure to dithiothreitol (DTT). Scanning electron microscopy revealed differences in biofilm ultrastructure between the two methods, including variation in appearance of ECM materials and morphology of resident cells, while light microscopy and staining with calcofluor white indicated that both biofilms contained polysaccharides characteristic of cellulose. Measuring susceptibility of biofilms to degradation by enzymes suggested differences in structurally important ECM molecules, with DTT biofilms having important protein and, to a lesser extent, cellulose components, and M63 biofilms having moderate protein, cellulose, and DNA components. Both biofilms conferred resistance to the bactericidal effects of amikacin and clarithromycin, with resident cells being killed at &gt;10-fold lower rates than planktonic cells at almost all concentrations. Though these comparisons indicate differences in biofilm responses by M. avium under differing conditions, they also suggest common features of biofilm formation including cellulose production and antimicrobial resistance.

Shiga toxin-producing Escherichia coli (STEC) are notorious foodborne pathogens capable of causing severe diarrhea and other life-threatening complications in humans. Cattle remain a major reservoir and asymptomatic carriers of STEC. In reservoir animals, the rectoanal junction (RAJ) serves as the primary colonization site of STEC playing a critical role in its transmission to humans through contaminated food sources. However, the molecular mechanisms behind the adaptation of STEC in the RAJ of the asymptomatic reservoir host and its subsequent infection of human colonic epithelial cells in an event of a foodborne transmission to cause diarrhea remain largely unexplored. This study aimed to unravel the intricate dynamics of STEC O157:H7 serotype in these two distinct host environments: bovine RAJ cells and human colonic epithelial cells, during initial colonization. In this context, comparative transcriptomics analysis was employed to investigate the differential gene expression profiles of STEC O157:H7 during its interaction with these cell types. The bacterial cells were cultured under controlled conditions to simulate the microenvironments of both bovine RAJ and human colonic epithelial cells. Using high-throughput RNA sequencing, we identified key bacterial genes and regulatory pathways that were significantly modulated in response to each specific host environment. Our findings reveal distinct expression patterns of bacterial genes involved in virulence, including adherence, metal iron homeostasis and stress response in STEC O157:H7 grown in bovine RAJ cells as op-posed to human colonic epithelial cells six hours post-infection. Additionally, the comparative analysis highlights the potential role of certain genes in host adaptation and tissue-specific pathogenicity. Furthermore, this study sheds light on the potential factors contributing to the survival and persistence of STEC O157:H7 in the bovine reservoir, and its ability to colonize in-testinal epithelium and cause disease in humans.

Irrigation and debridement using an irrigation solution is a fundamental step during the surgi-cal treatment of both acute and chronic periprosthetic joint infection (PJI). However, there is no consensus on the optimal solution, nor is there sufficient evidence on optimal irrigation time and combination of solutions. Therefore, it is necessary to determine which solution or combi-nation of solutions is most efficacious against biofilm, as well as the optimal irrigation time. We conducted an experimental in vitro model by inoculating stainless steel discs with ATCC strains of methicillin-susceptible Staphylococcus aureus, methicillin-resistant S. aureus, Pseudomonas aeru-ginosa, and a clinical strain of Staphylococcus epidermidis. The discs were all irrigated with com-monly used antiseptic solutions (10% and 3% povidone iodine, hydrogen peroxide, 3% acetic ac-id, and Bactisure™) for 1 min, 3 min, and 5 min and their combinations for 9 min (3 min each) vs. sterile saline as a positive control. We evaluated the reduction in biofilm based on colony form-ing unit (cfu) counts and, in combination assays, also based on cell viability and scanning elec-tron microscopy. All antiseptics alone reduced more than 90% of cfu counts after 1 min of irriga-tion; the worst results were for hydrogen peroxide and 3% acetic acid. When solutions were combined, the best results were observed for all those starting with acetic acid, in terms of both reduction of log cfu/ml counts and viable cells. We consider that a combination of antiseptic so-lutions, particularly that comprising the sequence acetic acid+povidone iodine+hydrogen per-oxide, would be the best option for chemical debridement during PJI surgery.

Effective oral care is a critical requirement to maintain high quality of life. Most oral diseases are caused by plaque (oral biofilm), which is also correlated with systemic diseases. A common method to remove biofilm is brushing teeth with a toothpaste. However, 3.5 billion people in the world have oral diseases, meaning that more efficient methods of removing biofilms are needed. We have developed a toothbrush applying bioelectric effect (BE) utilizing an electric force for biofilm removal. It demonstrated significantly higher biofilm removal efficiency than non-BE manual toothbrushes. Tests were performed in saline and toothpaste conditions using various pressure. Results showed that the BE toothbrush had a significantly higher biofilm removal efficiency in saline (0.5 N: 215.43 ± 89.92 %, 2.5 N: 116.77 ± 47.02 %) and in a toothpaste slurry (0.5 N: 104.96 ± 98.93 %, 2.5 N: 96.23 ± 35.16 %) than non-BE manual toothbrushes. Results also showed that BE toothbrushes were less dependent on toothpaste. This study suggests that the application of BE can be a new solution to plaque problems in oral care.

Biofilms are complex communities of microorganisms that adhere to surfaces and develop a protective matrix. The colonization of devices in the food and health care industries by microbial biofilms poses numerous risks. Existing antimicrobial agents often fail to penetrate the biofilm matrix, allowing the pathogen to grow and persist. The objective of this study was to evaluate the impact of MADIO PRO+ multipurpose disinfectant on Salmonella Typhimurium biofilm using crystal violet assay and FTIR spectroscopy. Results demonstrated that MADIO PRO+ multipurpose disinfectant significantly (p<0.05) inhibited biomass of S. Typhimurium biofilm and altered the structure of S. Typhimurium biofilm. In conclusion, MADIO PRO+ multipurpose disinfectant offers an advantage in biofilm control strategy. This discovery could help the food and health care industries to plan better microbial intervention strategies.

Cyanobacteria are promising organisms for the sustainable production of various biotechnologi-cal interesting products. Due to their energy production via photosynthesis, the cultivation of cyanobacteria expands the CO2 cycle. Most cyanobacteria form biofilms on surfaces in their natu-ral environment by surrounding the cells with a self-produced matrix of extracellular polymeric substances (EPS) that hold the cells together. These special growth properties need special reac-tors for cultivation. By immobilizing cyanobacteria on carriers, systems currently established in industry could also be used for biofilm formers. Various artificial carriers for immobilized growth of cyanobacteria and microalgae have already been described in the literature. However, the use of waste materials or natural biodegradable carriers would be more sustainable and is, therefore, the focus of this study. Dried Luffa cylindrica, zeolite, and corn stalks were investigated for their use as carriers for cyanobacteria. L. cylindrica was shown to be an excellent natural carrier for (i) Anabaena cylindrica (ii) Nostoc muscorum 1453-12a, and (III) Nostoc muscorum 1453-12b. Higher or at least similar growth rates were achieved when cyanobacteria were cultivated with L. cylindrica compared to submerged cultivation. Additionally, the production of EPS and C-phycocyanin was increased at least 1.4-fold in all strains by culturing on L. cylindrica. The improved growth could be explained on the one hand by the high surface area of L. cylindrica and its properties, and on the other hand by the release of growth-promoting nutrients from L. cylindrica to the medium.

Hydroxamic acid (HA) derivates displayed antibacterial and antifungal activities. HA with various numbers of carbon atoms (C2, C6, C8, C10, C12 and C17), complexed to different metal ions Fe(II/III), Ni(II), Cu(II) and Zn(II) were evaluated for their antimycobacterial activities and their anti-biofilm activities. Some derivates, among others HA12Fe2, inhibited the development of Mycobacterium tuberculosis, Mycobacterium bovis BCG and Mycobacterium marinum biofilms and could even attack pre-formed Pseudomonas aeruginosa biofilm. Proteomic profiles showed that the potential targets of HA10FeCl were mainly related to mycobacteria stress adaptation, involving cell wall lipid biosynthesis, drug resistance and tolerance, siderophore metabolism. This study provides new insights regarding the antimycobacterial activities of the HA and their complexes, especially about their potential antibiofilm activities.

Background: Antibiofilm activity of silver nanoparticles has been extensively investigated in common bacteria. Metallo-β-lactamase producing Gram-negative bacteria are hard-to-treat microorganisms with few therapeutic options, and silver nanoparticles were not evaluated on the biofilm of these bacteria. Objectives: The aim of this study was to evaluate the antibiofilm activity of a bone scaffold impregnated with silver nanoparticles in NDM-producing Gram-negative bacilli. Methods: Bone scaffolds from bovine femur were used for the tests and impregnated with silver nanoparticles (50 nm) by physical adsorption. Silver nitrate minimal inhibitory and bactericidal concentrations (MIC and MBC) were performed on NDM-producing Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Disc diffusion tests for silver nanoparticles susceptibility and quantification of biofilm production on plate and bone with sessile cell count were performed. Results: The MIC results demonstrated that silver nitrate had an antimicrobial effect on all microorganisms, inactivating the growth of isolates from a concentration of 8 µg/mL. MBC results showed that E. coli 16.211 was the only isolate to present MIC different from MBC, with a value of 16 µg/mL. Conclusion: Bone scaffolds impregnated with silver nanoparticles can significantly reduce biofilm, and it can be a strategic material to be used as an implant for different approaches.

Concrete cracks have a detrimental effect on the strength properties and durability of the structures. So, repairing of concrete cracks to recover their strength parameters is more important task in civil engineering. To repair concrete cracks, MICP has been widely analysed in recent times; but, zero research is conducted to deeply investigate the repair effects of MICP on concrete cracks with rough surface by using the theoretic model. In current research, MICP with a novel mathematical model was attained by taking the precipitation of calcium carbonate (CaCO3), ureolysis, suspended biomass, geochemistry, transport of solute and biofilm growth. Furthermore, crack repair experiments were performed to check the workability of the new mathematical method. The outcomes revealed that the designed suspended biomass concentrations in cracks diminished step by step. The comparison in between the experimental results and calculated results verified the precision of migration behaviour of the suspended biomass. At the inlet, the solute concentrations and biofilm volume fractions was higher, causing in rise of yield amounts for calcium carbonate. The consumed solutes concentrations were higher for cracks of less rough surface, ultimately causing in smaller sonic time; and the values of sonic time for upper portions of cracks was smaller, showing good repair impacts. The recommended mathematical model provides a better tool that controls repair time and microbial metabolism process to report a new adjustive, bioremediation and biomineralization to concrete, which could provide a firm base for remediation of material in civil engineering field.

Background: The biofilm-forming bacteria Porphyromonas gingivalis (P. gingivalis) is primarily responsible for periodontal disorders, which continue to be a global health issue. Despite the widespread use of antibiotics like metronidazole, other potent therapeutic a crucial quorum sensing molecule implicated in the formation of P. gingivalis biofilm. Approaches are now being explored due to the growing challenge of antibiotic resistance. Objective: In particular, chemicals from Symphytum Officinale (S) and Panax Ginseng (G) plants will be examined in this study to assess if they have the ability to inhibit biofilm and to prevent the development of acylated homoserine lactones (AHLs), a quorum sensing molecule. Materials and Methods: With Metronidazole serving as a control, the antibacterial effects of these substances (Symphytum Officinale and Panax Ginseng) were examined against a standard strain and a clinical isolate of P. gingivalis. Dilutions of these plant extracts were used either alone (G+S) or in conjunction with metronidazole (G+S+F), to assess their antibacterial activity using antibacterial susceptibility test (inhibition zone), biofilm inhibition and disruption assay (optical density) and quorum sensing inhibition assay (AHL). Results: The combinations of Symphytum officinale, Panax Ginseng and metronidazole (S+G+F) showed the maximum effectiveness with highest zone of inhibition (25.000±0.001 mm) and biofilm inhibition (98.46%), and were comparable to G+S (inhibition zone of 24.341±0.593 mm and biofilm inhibition of 97.76%), and significantly different in the degree of biofilm inhibition with different treatment scenarios. Additionally, the plant's extracts and combinations are specific concentrations had a significant effect on the suppression of the generation of AHL (p &lt; 0.05). Conclusion: According to preliminary research, these plant-derived substances, especially when paired with metronidazole, significantly inhibited the growth of P. gingivalis biofilm providing valuable information for the development of innovative therapeutic approaches for periodontitis and other biofilm-associated illnesses.

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.

Concrete is the most utilized construction material worldwide. In the marine environment, it is subject to chemical degradation through reactions with chloride (the most important ion), sulfate and magnesium ions in seawater and to biodeterioration resulting from biological (initially microbiological) activities, principally acid production. These two types of corrosion are reviewed and the failure of attempts to predict the degree of deterioration resulting from each is noted. Chemical (abiotic) corrosion is greatest in the splash zone of coastal constructions, while phenomenological evidence suggests that biodeterioration is greatest in tidal zones. There have been no comparative experiments to determine the rates and types of microbial biofilm formation in these zones. Both chemical and microbiological concrete deterioration are complex and have not been successfully modeled. The interaction between abiotic corrosion and biofilm formation is considered. EPS can maintain surface hydration, potentially reducing abiotic corrosion. The early marine biofilm contains relatively specific bacterial colonizers, including cyanobacteria and proteobacteria; these change over time, producing a generic concrete biofilm, but adhesion of microorganisms to concrete in the oceans is little investigated. The colonization of artificial reefs is briefly discussed. Concrete appears to be a relatively prescriptive substrate, with modifications necessary to increase colonization for the required goal of increasing biological diversity.

Enteroccoccus faecalis is a commensal that is responsible for numerous infections in surgical sites, urinary tract and bloodstream. It is of growing concern given its propensity to affect the elderly population where there is a high prevalence of undiagnosed degenerative valvular disease and the with more invasive procedures and implanted medical devices. Its actions are mediated by specific characteristics of the bacterium such as pili activity and biofilm formation. This confers significant resistance toward a multitude of antibiotic therapy, especially in endocarditis. The current guidelines advocate antimicrobial therapy but the emergence of resistant strains has added a degree of complexity to the management of these patients, especially with the advent of transcatheter therapies which are often used in patients who are poor surgical candidates. Their presentations are often variable with generalized symptoms and can be diagnostically challenging. We present our experience of a case study involving an octogenarian with a TAVI valve who developed endocarditis and performed a literature review to highlight treatment algorithms for these cases.

Biofilm formation and lipopolysaccharide (LPS) are implicated in the pathogenesis of gastrointestinal (GI) diseases caused by Gram-negative such as Escherichia coli and Salmonella enterica serovar Typhimurium. Grape seeds, wine industry by-products, have antioxidant, antimicrobial, and anti-inflammatory activities. In the present study, the protective effect of procyanidin-rich grape seed extract (prGSE), from unfermented pomace of Vitis vinifera cv Bellone, on bacterial LPS-induced oxidative stress and epithelial barrier integrity damages has been studied in a model of Caco-2 cells. The in vitro activity of prGSE against formation of biofilm of S. Typhimurium and E. coli, has been investigated. In vivo, prGSE activity using infected Galleria mellonella larvae has been evaluated. The results showed that the prGSE, if administered with LPS, can significantly reduce the LPS-induced permeability alteration. Moreover, the ability of the extract to prevent Reactive Oxygen Species (ROS) production induced by LPS treatment of Caco-2 cells has been demonstrated. prGSE inhibited the biofilm formation of E. coli and S. Typhimurium. In in vivo activity, increased survival of infected G. mellonella larvae after treatment with prGSE has been demonstrated. In conclusion, grape seed extracts could be used in the reduction of GI damage caused by bacterial endotoxin and biofilm of Gram-negative bacteria.

Microbiological risk associated to abiotic surfaces is one of the most important issue worldwide. Surface contaminations by pathogenic bacterial biofilms or adherent cell affect a number of sectors including medical services, food industries, human services, and the environment. There is a need to synthesize or to setup novel antimicrobials. Terpenes are usually found in essential oils and have potent antimicrobial activities. However, the direct use of these molecules is often inefficient due to their low water solubility, loss of volatile compounds, thermal degradation, oxidation and toxicity. The need for biosourced compounds with antimicrobial activity, low toxicity and low cost promote the search for new stable metal complexes based on terpene ligands. This will enable the manufacture of value-added products with a lower environmental impact, as well as the production of high value added commodities. The goal of this review is to discuss the development of novel antimicrobial complexes derived from terpenes. In addition, this review explored how to improve their bioactivities and characteristics by using a formulation based on microencapsulation.

Round bodies in spirochete cultures have been a controversial subject since their description seven decades ago. We report the existence of round bodies (spherical cells) in cultures of Mucispirillum schaedleri, a spiral bacterium phylogenetically distant from spirochetes. Furthermore, when grown in biofilms, M. schaedleri demonstrates a unique morphology known as cording, which has been previously described only in mycobacteria. Thus, M. schaedleri has two distinct features, each previously thought to be unique to two different phylogenetically distant groups of bacteria.

Quorum sensing (QS), a well-established phenomenon in microorganisms, involves the communication between cells through chemical signals, which is dependent on cell density. Extensive research has been conducted on this microbial ability, encompassing the early stages of understanding QS to the latest advancements in the identification and characterization of its mechanisms. This minireview comprehensively examines the role of QS in various aspects, including biofilm formation, virulence in pathogenic bacteria such as Helicobacter pylori and Pseudomonas sp., as well as its influence on biogeochemical cycling in deep-sea environments. Furthermore, future progress in the field will be achieved by combining state-of-the-art methods for observing QS in the deep sea with a deeper understanding of the underlying processes, which will facilitate the engineering of microorganisms for improved degradation of persistent environmental pollutants and other biotechnological applications.

Inhibition of quorum sensing (QS)-dependent biofilm formation and virulence is extensively investigated as a novel approach to combat bacterial pathogens by impeding their ability to cause antibiotic-tolerant diseases. Such strategies are considered a promising alternative to conventional antibacterial therapy since interrupting the central cell-to-cell communication system imposes less selective pressure on the target pathogen. In this study, novel hybrid compounds composed of anthranilic acids substituted with halogens at different positions of the phenyl ring, and 4-(2-aminoethyl/4-aminobuthyl)amino-7-chloroquinoline linked via 1,3,4-oxadiazole were synthesized using standard procedures. Their anti-QS activities were evaluated using Chromobacterium violaceum ATCC31532 (anti-biofilm and bactericidal activities) and Pseudomonas aeruginosa PAO1 (anti-biofilm/-virulence activities). The results showed that compounds 15–19 and 23 inhibited the production of violacein, the QS-inducible pigment, in C. violaceum to a similar extent as the model QS inhibitor - quercetin (83.5–90%). Compound 15 exhibited the strongest effect on P. aeruginosa in the anti-biofilm screening, reducing its ability to form biofilm by almost 50%, while compounds 16 and 19 were able to reduce the biofilm formation by approximately 30%. However, compound 23 did not demonstrate significant anti-biofilm activity and only inhibited pyocyanin production in P. aeruginosa. In conclusion, this study suggests that 1,3,4-oxadiazoles 15, 16, and 19 are the most promising compounds for future research as novel QS inhibitors against Gram-negative bacteria equipped with different QS signaling pathways.

The use of metal oxide nanoparticles as an alternative antimicrobial agent has gained attention due to the increasing problem of antibiotic resistance. Understanding its properties and potential benefits can contribute to the development of more effective and sustainable treatments in veterinary medicine. The aim of this study was to characterize TiO2-NP formulations and evaluate their antibacterial and wound healing abilities. The diameters and zeta potentials were determined using the Zetasizer in conjunction with dynamic light scattering. The agar-well diffusion method, time-kill kinetic assay and crystal violet assay were used to evaluate their antimicrobial activities. Wound healing assays were conducted both in-vitro and in-vivo. The study demonstrated that TiO2-NP formulations exhibit significant antimicrobial properties against various bacterial strains such as S. aureus and E. coli. No measurable E. coli growth was observed within a 15-mins period following exposure to TiO2-NP formulations. The TiO2-NP formation can improve wound healing by enhancing cell migration and collagen formation in both in-vitro and in-vivo conditions. In summary, our study suggests that TiO2-NP has the potential for use as an antimicrobial agent for animal wound treatment due to its ability to suppress bacterial growth and biofilm formation, as well as to enhance wound healing.

Background: The important periodontal disease pathogen Porphyromonas gingivalis produces large biofilms that increase its pathogenicity. Finding natural antimicrobial agents is crucial because of the rise in antibiotic resistance. Objective: The purpose of this study was to determine if plant extracts such as Symphytum officinale (S) and Panax ginseng (G) were effective against P. gingivalis separately and in combination with a common antibiotic Metronidazole (F). Materials and Procedures: Six different dilutions were produced the plant extracts and antibiotic separately and in combination with G and F and S and F using two-fold serial dilution technique. To evaluate the effects of these substances biofilm inhibition experiments were conducted. Plaque samples were collected from periodontitis patients to isolate P. gingivalis and standard strain of P. gingivalis (ATCC 33277) were bought. Additionally, Acylated Homoserine Lactones (AHLs) detection was carried out to look for any activity that would interfere with quorum sensing. GraphPad prism was used for statistical analysis with p value &lt; 0.05. Results: The combinations of Symphytum Officinale and Metronidazole (S+F) showed the maximum effectiveness in biofilm inhibition (98.7%), which was better than G+F (98.2%) with substantial variations in biofilm inhibition levels in different treatment regimes. Notably, the isolate from the patient was more active than the standard strain. Additionally, the plant extracts and their combinations at particular dilutions had notable inhibitory effects on the generation of AHL (p &lt;0.05). Conclusion: The study highlights the possibility of Symphytum Officinale and Panax Ginseng as effective treatments for P. gingivalis biofilm and AHLs, both on their own and in combination with Metronidazole. These organic substances may open the door to cutting-edge methods of treating periodontal disorders.

There was no significant difference in bacterial adhesion between the 3 bone graft types tested, regardless of the bacterial strain used (p &gt; 0.22). After 72 hours of culture, there was no significant difference between the Fresh and Frozen bone groups, while the number of CFU in the Decellularised group was significantly lower (p &lt; 0.01), averaging -0.72 +/- 0.08 lg, -0.20 +/- 0.01 lg and -0.78 +/- 0.48 lg with S. epidermidis, S. aureus and E. coli respectively. Absolute values differences are low, and considering fresh bone (equivalent to autograft) as the gold standard due to its low infection rates in clinical studies, we can conclude that adhesion and biolfilm development characteristics are similar between Fresh, Frozen and Decellularised bone grafts..

Caries are lesions caused by acidic compounds derived from the metabolism of bacteria such as streptococci. It is not merely the presence of acidogenic bacteria that causes caries but an imbalance in the oral biofilm microhabitat and its behavior. One factor underlying biofilm formation is quorum sensing (QS), that in gram-positives relies on peptidic molecules, whereas in gram-negatives is driven by small diffusible signals. Strategies based on QS inhibition have been proposed as alter-natives to antimicrobial therapies. Here, we investigate the antibiofilm potential of the lactonase enzyme Aii20J, previously reported as effective against biofilms of periodontal disease origin. We generated in vitro polymicrobial biofilms dominated by gram-positive taxa using supragingival samples from caries-free and caries-active children. The effect of Aii20J on the biofilms was evalu-ated regarding its biomass-reducing ability, as assessed with crystal violet assay, and its effects on the bacterial composition of the polymicrobial biofilms, as assessed by 16S community profiling. We describe significant biomass reductions upon Aii20J exposure without significant changes in bac-terial composition at the genus level. Our results support the use of Aii20J to prevent oral biofilm formation while highlighting the influence of the polymicrobial environment on bacterial commu-nities and their response to antibiofilm treatments.

The lactoperoxidase (LPO) system shows promise in the prevention of dental caries, a common chronic disease. This system has antimicrobial properties and is part of the non-specific antimicrobial immune system. Understanding the efficacy of the LPO system in the fight against biofilms could provide information on alternative strategies for the prevention and treatment of caries. In this study, the enzymatic system was modified using four different (pseudo)halide substrates (thiocyanate, thiocyanate-iodide mixture, selenocyanate, and iodide). The study evaluated the effects of such modifications on the ability of Streptococcus mutans to form a biofilm, the synthesis of insoluble polysaccharides, the synthesis of lactate, the consumption of glucose and sucrose, the concentrations of intracellular NAD+ and NADH and the efficiency of transmembrane glucose transport by phosphoenolpuryvate PEP-carbohydrate phosphotransferase (PTS). The results showed that the LPO-iodide system had the strongest inhibitory effect on biofilm growth and lactate synthesis (complete inhibition). This was associated with an increase in the NAD+/NADH ratio and an inhibition of glucose PTS activity. The LPO-selenocyanate system showed a moderate inhibitory effect on biofilm biomass growth and lactate synthesis. The other systems showed relatively small inhibition of lactate synthesis and glucose PTS but no effect on the growth of biofilm biomass. This study provides a basis for further research on the use of alternative substrates of the LPO system, particularly the LPO-iodide system, in the prevention and control of biofilm-related diseases.

Based on previous studies of our group in which we demonstrated that dalbavancin loaded in bone cement had good elution capacity for the treatment of biofilm-related periprosthetic infections, we now assess the anti-biofilm activity of dalbavancin and compare it with that of vancomycin up to a 3-month period. We performed an in vitro model based on calculation of percentage reduction of log cfu/ml counts of sonicated steel discs contaminated with Staphylococci and further exposed to bone cement discs loaded with 2.5% or 5% vancomycin and dalbavancin at each study period (24 hours, 48 hours, 1 week, 2 weeks, 6 weeks, 3 months). In addition, we tested the anti-biofilm activity of eluted vancomycin and dalbavancin at each study period based on a 96-well plate model assessing percentage reduction of metabolic activity. Overall, dalbavancin showed a significant concentration decrease from 2 weeks of incubation and maintain its anti-biofilm activity up to 3 months, whereas, despite vancomycin showed a significant decrease at 1w and then it gradually increased, its anti-biofilm activity was significantly lower. Dalbavancin percentage reduction cfu/ml counts were higher than those of vancomycin, both at 2.5% and 5% concentrations. Reduction of log cfu/ml counts were higher for S. epidermidis than for S. aureus, being more notable for 5% dalbavancin at month 3. In addition, percentage reduction of metabolic activity also decreased at 3 months in 5% dalbavancin and 5% vancomycin, being more notable in the last.

Helicobacter pylori is a gastric pathogen that infects nearly half of the global population and is recognized as a group 1 carcinogen by the Word Health Organization. The global rise in antibiotic resistance has increased clinical challenges in treating H. pylori infections. Biofilm growth has been proposed to contribute to H. pylori’s chronic colonization of the host stomach, treatment failures, and the eventual development of gastric diseases. Several components of H. pylori have been identified to promote biofilm growth, and several of these may also facilitate antibiotic tolerance, including the extracellular matrix, outer membrane proteins, the coccoid morphology, modulated metabolism, efflux pumps, and virulence factors. Recent developments in therapeutic approaches targeting H. pylori biofilm have shown that synthetic compounds, such as small molecule drugs and plant-derived compounds, are effective at eradicating H. pylori biofilms. These combined topics highlight the necessity for biofilm-based research in H. pylori, to improve current H. pylori targeted therapeutic approaches and alleviate relative public health burden. In this review we discuss recent discoveries that have decoded the life cycle of H. pylori biofilms and current biofilm targeted treatment strategies.

Bacterial biofilms can cause widespread infection. In addition to causing urinary tract infections and pulmonary infections in patients with cystic fibrosis, biofilms can help microorganisms adhere to the surfaces of various medical devices, causing biofilm-associated infections on the surfaces of biomaterials such as venous ducts, joint prostheses, mechanical heart valves, and catheters. Biofilms provide a protective barrier for bacteria and provide resistance to antimicrobial agents, which increases the morbidity and mortality of patients. This review introduces the formation process and drug resistance mechanism of biofilms in detail, and further summarizes the main characteristics of clinical persistent infection caused by biofilms and the many methods of treating biomaterial-related biofilm. This provides ideas and directions for the development of new biofilm infection strategies related to therapeutic materials.

The increased emergence of multidrug-resistant Helicobacter pylori influences the prevention of stomach cancer. Zingiber officinale is a plant usually used in folk medicine to treat a variety of diseases involving infections, nausea, vomiting, peptic ulcer, dyspepsia, and inflammation. This study was conducted to evaluate the ability of Z. officinale extract to combat resistant H. pylori. The disc diffusion, microdilution, and microplate assays were performed to evaluate the susceptibility to antibiotics, and the antibacterial and antibiofilm activities of the Z. officinale extracts. Using the checkerboard method, the combined effects of the gentamicin and Z. officinale extract were investigated. In addition, anti-inflammatory activity and GC-MS analysis were determined by the modified protocol. According to the findings, H. pylori isolates exhibited resistance rates of 56.33, 50.0, and 45.85 for metronidazole, gentamicin, and tetracycline, respectively. The methanolic extract of Z. officinale had the strongest effectiveness against resistant H. pylori isolates with MIC of 20.0 to 50.0 µg/ml against both H. pylori isolates and the stranded strain NCTC 11637. Z. officinale extract suppress the biofilm formed by H. pylori isolates with a percentage of 92.96% at 50.0µg/ml, compared with 97.19% for gentamicin at the same concentration. According to FICI values, combination of methanolic Z. officinale extract to gentamicin increases bacterial sensitivity to such drugs. Moreover, the Z. officinale extract exhibits strong anti-inflammatory activity. The GC-MS analysis of Z. officinale extract exhibits 17 different chemical compounds. Conclusions: The Z. officinale extract contain the anti-inflammatory compound gingerol as the main constituent which inhibits the growth of H. pylori and its biofilm, are a promising natural therapeutic alternative or enhance antibiotics activity

The detection of antibiotic-resistant facultative pathogenic bacteria in surface waters is common in the present day. However, there is limited understanding of the factors that influence the spread and stabilization of resistance in this habitat, particularly regarding the role of biofilms. Despite the perceived differences between sediments, biofilms, and open water, their potential contribution to the long-term maintenance of resistances remains unclear. In this study, we investigated Escherichia coli isolates obtained from the Mur and Drava rivers in Austria. Samples were collected from both the water column and sediment at two locations per river: upstream and downstream of an urban area, including a sewage treatment plant. The iso-lates were subjected to antimicrobial susceptibility testing against 21 antibiotics belonging to seven distinct classes. Additionally, any isolates exhibiting an extended-spectrum beta-lactamase (ESBL) or carbapenemase phenotype were further analyzed for the presence of specific antimi-crobial resistance genes. E. coli isolates obtained from the two rivers exhibited resistance to at least one of the tested anti-biotics, with rates of 25.83% and 23.66% respectively. The most prevalent antimicrobial re-sistances observed were towards ampicillin, amoxicillin-clavulanic acid, tetracycline, and na-lidixic acid. Surprisingly, there was a similar proportion of resistant bacteria observed in both open water and sediment samples, contrary to expectations. The difference in resistance levels between samples collected upstream and downstream of the cities was minimal. Out of the total isolates, 13 E. coli were found to carry ESBL genes with one isolate carrying the gene for KPC-2 carbapenemase. There were no significant differences between the biofilm (sediment) and open water samples in the occurrence of antimicrobial resistance. Even the difference between the samples upstream and downstream of the cities and their wastewater treatment plants was minor. There seems to be no evidence of a large adaptive effect in this analysed biofilm population of E. coli. The un-typical phenotype of the KPC-producing and some of the ESBL-producing E. coli from this study could, however, be an indication that such adaptation effects generally exist in water.

Objective: The purpose of this study was to evaluate the surface texture and biofilm adhesion of veneered or CAD/CAM milled zirconia (partially stabilized with yttrium) after professional oral hygiene procedures. Samples (4x4 mm, thickness 2 mm; n = 72) were separated from zirconia blanks (3Y-TZP-LA). One group was veenired with ceramics and the other group of samples was CAD/CAM milled. Each group had 2 subgroups: polished and glazed. The samples were subjected to simulated strokes of professional brushing using abrasive paste and ultrasonic scaling. Parameters of surface micromorphology and receptivity to biofilm were calculated before and after simulating the given methods of professional maintenance of oral hygiene. The characteristics of zirconia surface were evaluated by scanning electron microscopy (SEM). Microbial bacterial/fungal species (Staphylococcus aureus, Streptococcus sanguinis and Candida albicans) were used and cultured on the respective sterilized zirconia surfaces. The amount of biofilm formation on zirconia surface was quantified by colony forming unit (CFU) counts. Results: SEM analysis showed the greatest change in surface microtopography after the use of ultrasonic scaling, in glazed zirconia samples. Less formation of colonies on the surface CAD/CAM milled zirconia restorations was observed. Conclusion: Routine methods of professional maintenance of oral hygiene can damage the surface of glazed zirconia restorations.

Prevalence of antimicrobial-resistant bacteria has become a major challenge worldwide. Methicillin-resistant Staphylococcus aureus (MRSA)—a leading cause of infections—forms biofilms on polymeric medical devices and implants, increasing their resistance to antibiotics. Antibiotic administration before biofilm formation is crucial. Raman spectroscopy was used to assess MRSA biofilm development on solid culture media from 0 to 48 h. Biofilm formation was monitored by measuring DNA/RNA-associated Raman peaks and protein/lipid-associated peaks. The search for an antimicrobial agent against MRSA biofilm revealed that Eugenol was a promising candidate as it showed significant potential for breaking down the biofilm. Eugenol was applied at different times to test the optimal time for inhibiting MRSA biofilms, and the Raman spectrum showed that the first 5 h of biofilm formation was the most antibiotic-sensitive time. This study investigated the performance of Raman spectroscopy coupled with Principal Component Analysis (PCA) to identify planktonic bacteria from biofilm conglomerates. Raman analysis, microscopic observation, and quantification of the biofilm growth curve indicated early adhesion from 5 to 10 h of incubation time. Therefore, Raman spectroscopy can help in monitoring biofilm formation on a solid culture medium and performing rapid antibiofilm assessments with new antibiotics during the early stages of the procedure.

Cryptococcus neoformans is a pathogenic fungus that causes cryptococcosis, a significant secondary infection in immunocompromised individuals with immune-suppressive related symptoms from HIV infection and organ transplants. Fungaemia occurs via the respiratory route and spreads by tissue invasion into other body parts. Enzymes and membrane-associated permeases/transporters are accessory proteins deployed to enhance the survival, adaptation, and infection caused by Cryptococcus species. The nutrient bioavailability determines the functional turnover rate of these proteins in the immediate fungal environment. Low oxygen levels in the internal organs, essential micro-elements locked in the storage proteins, catabolite repression, phagolysosomal low glucose level and pH, tight junction, and extracellular matrixes are challenges to the survival of this pathogen in the host. This review identifies key hydrolytic and metabolic enzymes and permeases/transporters as essential weapons of virulence in addition to survival, tolerance, resistance, adaptation, and infection in humans. Under the regulation of different transcription factors, these proteins are released in response to nutrient sensors designed to siphon the host nutrients and induce infection in predisposed individuals. The extracellular secretory vesicles called “exosomal virulence bag” also harbour cryptococcal urease, laccase, phosphatase, and capsular components as additional secretory protein weapons for immune evasion, tissue invasion and persistence.

Due to the progression of antimicrobial resistance, Photodynamic (aPDT) and Sonodynamic (SDT) Therapies arose as promising approaches for microbial control. Recently, the combination of both therapies, called Sonophotodynamic Therapy (SPDT), have shown greater effects than the single treatments. This study evaluated the effects of aPDT, SDT and SPDT mediated by curcumin on the metabolism, adhesion capacity, biofilm formation ability and structural alteration in the Staphylococcus aureus biofilm. Moreover, possible antimicrobial mechanisms involved, such as the production of reactive oxygen species (ROS) and the degradation spectrum of curcumin by light, ultrasound and light+ultrasound, were measured. SPDT was more effective to inactivate the biofilm than aPDT and SDT. All treatments reduced the adhesion ability of the bacteria and it is probably related to the metabolism cell reduction. Regarding to the biofilm formation ability, all treatments reduced the total biomass. One possible mechanism involved in the inactivation is the ROS production observed. Curcumin had a significantly decay in its absorbance with the application of light, and a slighter one caused by the ultrasound. Finally, all treatments impacted the biofilm components and structure, reducing the cells and matrix. In conclusion, SPDT was more effective in the inactivation, and all treatments had the same effect in the virulence factors evaluated.

Pseudomonas aeruginosa is an antibiotic-resistant priority pathogen as listed by the World Health Organization. P. aeruginosa, a gram-negative, rod-shaped bacterium, is frequently encountered in hospital settings as an opportunistic pathogen in nosocomial infections. P. aeruginosa has shown high antibiotic resistance, which has been attributed to several mechanisms, such as intrinsic, acquired, and adaptive resistance. This study investigates several genes which may be attributed to the acquisition of antibiotic resistance in the bacteria P. aeruginosa, as it transitions from its planktonic form to the more threatening and resistant biofilm form. Subsequently, the study assesses the comparative efficacy of three antibiotics, Ofloxacin (OFX), Tobramycin (TOB), and Ceftazidime (CAZ), in altering the expression levels of the identified multidrug efflux pump genes associated with the ability to extrude antibiotics from the cell when in the biofilm form. Efflux transporter gene expression in P. aeruginosa was conducted via extraction of total RNA in planktonic and biofilm- both untreated and treated - with Tobramycin (TOB), Ofloxacin (OFX), and Ceftazidime (CAZ). Real-time quantitative reverse transcriptase PCR was employed to analyze alterations in expression levels of the Mex A, Mex B, Mex X, Mex Y, OprM, and RPSL genes in the collected samples. In samples where no antibiotics were administered, an increase in expression of the Mex B efflux pump gene was observed compared to all other efflux pump genes in the biofilm form, providing multidrug resistance when active. The gene of interest, Mex B, was assessed for antibiotic resistance by P. aeruginosa culturing in the planktonic and biofilm forms with simultaneous treatment with TOB, OFX, and CAZ. Of the three antibiotics used, OFX showed more effectiveness in preventing biofilm growth by reducing the expression level of the Mex B efflux pump gene in the biofilm form, making P. Aeruginosa more antibiotic sensitive to OFX. TOB has similar results compared to OFX but was slightly less effective in reducing the expression of Mex B. Conversely, CAZ was not effective in reducing expression of the Mex B gene in the biofilm form or the planktonic form and was determined to be ineffective at eradicating the organism.

Of late, the focus has been shifted towards quorum sensing inhibitors which reduce bacterial virulence and lower the probability of resistance and refining infections. In this work, meta-bromo-thiolactone (mBTL), a potent quorum and virulence inhibitor against Staphylococcus aureus and MRSA phenotypes, was formulated in chitosan nanoparticles (ChNPs) using ionic gelation method. mBTL-loaded-ChNPs were characterized for particle size, polydispersity index, zeta potential. Morphology was visualized by Transmission Electron Microscopy (TEM), drug release profile and antibiofilm analysis using Confocal Laser Scanning Microscope (CLSM) and Scanning Electron Microscopy (SEM) were performed. Synthesized mBTL-loaded-CNPs showed homogenized nano-size particles ranging from 158+1.3 to 284+5.6 nm with spherical particles that exhibited sustainable release profile over 48 hr at 37 °C. These findings revealed successful preparation of mBTL-loaded-ChNPs, that further showed effective antibiofilm activity at MIC50 (0.5 mg/mL) where all strains displayed reduced biofilm formation compared to untreated strains. CLSM results showed a significant reduction in the number of viable cells, indicating the effectiveness of m-BTL as an antibacterial agent. SEM analysis permitted visualization of biofilm structure in relation to the spatial localization of important biofilm matrix components, the formed biofilms were clearly distinguished in the SEM images. Bacterial cells in the control group were enclosed in thick biofilms. In contrast, there was a considerable reduction in biofilm production when mBTL was present, where bacterial cells seemed less ordered and more scattered with no detectable biofilms. In conclusion, mBTL-loaded-ChNPs is a potential alternative treatment to overcome antimicrobial resistance and condensed MRSA infections.

For this research, a comparative evaluation was performed in which the addition of 3D-printed biocarriers fabricated with 13X and Halloysite (13Χ-Η) and commercial Kaldnes K1 biocarriers were evaluated as opposed to the non addition of biocarriers in a semi-pilot scale MBBR-MBR unit. For the evaluation of the MBBR-MBR efficiency, various physicochemical parameters were measured while static light scattering and optical microscopy observations were additionally used. Biofilm extracted from the biocarriers was also evaluated. It was observed that in the MBBR-MBR K1 unit, the membrane filtration improved while in the MBBR-MBR 13X-H unit the membrane fouling rate was the same as in the control MBBR-MBR unit. This is due to the production of large amount of SMP which resulted from the large amount of biofilm created in the 13X-H biocarriers. An optimal biodegradation of the organic load was concluded for all three MBBR-MBR units. The nitrification and denitrification processes were improved at the MBBR-MBR units using 13X-H and K1. The dry mass produced on the 13X-H biocarriers was three orders of magnitude larger than that produced on the K1. Finally, it was observed that mostly EPS was produced in the biofilm of K1 biocarriers while in the biofilm of 13X-H mostly SMP.

In the present work, a comparative evaluation of an MBBR unit performance was carried out for the following cases: when adding 3D-printed biocarriers fabricated with 13X and bentonite, when using K1 commercial biocarriers and when not adding biocarriers at all. For the evaluation of the MBBR efficiency, various physicochemical parameters were measured, while static light scattering and optical microscopy observations were additionally used. Finally, biofilm extracted from the biocarriers was evaluated. The findings suggest that there is an optimal biodegradation of the organic load in all MBBR units. The nitrification and denitrification process were improved at the 3D MBBR as compared to the control MBBR and MBBR K1. The dry mass of the biofilm in the 3D-printed biocarriers was two orders of magnitude larger than the one in the K1 biocarriers. What is more, in the K1 biocarriers the mass of the biofilm varied in relation to time, due to the fact that it could not be kept inside the holes, something that was not observed to happen with the 3D-printed biocarriers. Finally, it was observed, mostly in the 3D MBBR and less in the K1 MBBR, that the growth of nitrifying bacteria and heterotrophs inside the units increased the biomass production in the form of SMP, which in turn favored the adhesion of biomass on the surface of biocarriers.

Oral diseases remain a major health problem worldwide, with the World Health Organisation reporting that oral health neglect affects almost half of the world’s population. Quorum sensing molecules (QSMs) influence oral biofilms in various ways with knowledge of direct oral QSM-host interaction being limited, and such studies could provide more insight into the cross-kingdom communication occurring during oral disease development. This review aims to explore the literature on oral QSM-host interaction and to highlight areas of advancement in this field. QSM CSP-1 produced by Gram-positive oral bacteria was found to interact with T2R receptors, activating NF-kB signalling and leading to remodeling of the cytoskeleton. AI-2 in the oral cavity was found in various studies to elicit an inflammatory response in specific oral cells. Overall AHL detection methods remain an area for development, through which greater understanding of oral QSMs’ influence on host cells can be achieved. In conclusion, from the current literature it can be inferred that that QSMs are utilised by host cells to detect bacterial presence and in the majority of cases elicit an immune response towards the environmental QSMs. This may provide a base to target QSMs as novel treatment of oral diseases.

Worldwide, oral lesions and cancers are still being significant public health conditions. Thus, an introduction of new oral healthcare protocols is becoming essential. Oral diseases are related to many causative factors, manly dental plaque/biofilm due to poor hygiene. New anti-biofilm therapies are needed to develop. The strategies of anti-biofilm therapies should help to control biofilm formation and microbial attachment to dental surfaces. The present review aimed to provide a comprehensive over-view on evidence related to the potential utility of topical oxygen therapy (BlueM formula) as novel oral care therapies in clinical practice.

Acinetobacter baumannii (AB) is a bacterium that causes infections, particularly in immunocompromised patients. Treatment is challenging due to biofilm formation by AB strains, which hinders antibiotic effec-tiveness and promotes drug resistance. The aim of our study was to analyze the biofilm-producing capacity of AB isolates from various forms of infections in relation to biofilm-related genes and their drug resistance. We tested one hundred isolates for biofilm formation using the crystal violet microplate method. Drug re-sistance analyses were performed based on EUCAST and CLSI guidelines, and biofilm genes were detected using PCR. All tested strains were found to form biofilms, with 50% being ICU strains and 72% classified as strong biofilm-producers. Among these, 87% were extensively drug-resistant (XDR) and 2% were extra extensively drug-resistant (E-XDR). The most common gene set was bap, bfmS, csuE, and ompA, found in 57% of all isolates. Our research has shown that, regardless of the form of infection, biofilm-forming strains can be expected among AB isolates. The emergence of E-XDR and XDR strains among non-ICU infections highlights the necessity for the rational use of antibiotics to stop or limit the further acquisition of drug re-sistance by A. baumannii.

Rapid developing antimicrobial resistance due to broad antibiotic utilisation in healthcare and food industries and the non-availability of novel antibiotics represents one of the most critical public health issues worldwide. The current advances in nanotechnology allow new materials to address drug-resistant bacterial infections in specific, focused and biologically safe ways. The unique physicochemical properties, biocompatibility, and wide range of adaptability of nanomaterials that exhibit photothermal capability can be employed to develop the next generation of photothermally induced controllable hyperthermia as antibacterial nanoplatforms. Here, we review the current state-of-the-art in different functional classes of photothermal antibacterial nanomaterials and the strategies to optimise antimicrobial efficiency. The recent achievements and trends in developing photothermally active nanostructures, including plasmonic metals, semiconductor, carbon-based, and organic photothermal polymers, and antibacterial mechanisms of action, including anti-multidrug resistant bacteria and biofilms removal, will be discussed. Insights into mechanisms of the photothermal effect and various factors influencing photothermal antimicrobial performance, emphasising the structure–performance relationship, are discussed. We will examine the photothermal agents’ functionalisation for specific bacteria, effects of near-infrared light irradiation spectrum, or active photothermal materials for multimodal synergistic-based therapies to minimise side effects and maintain low cost. Most relevant applications are presented, such as anti-biofilm formation, biofilm penetration or ablation, and nanomaterial-based infected wound therapy. Practical antibacterial applications employing the photothermal antimicrobial agents, alone or in synergistic combination with other nanomaterials, are considered. Existing challenges and limitations in photothermal antimicrobial therapy and future perspectives are presented from the structure, function, safety, and clinical potential points of view.

Background: The objective of the present study was to evaluate the formation of biofilm in bone patellar tendon bone grafts (BPTB grafts) and to compare it to the formation of biofilm formation in quadrupled hamstring anterior cruciate ligament grafts (4xHt graft). Methods: A descriptive in vitro study was conducted. One 4xHt graft and one BPTB graft were prepared. They were then contaminated with a strain of S. epidermidis. Later, a quantitative analysis was carried out by means of microcalorimetry and sonication with plating. Additionally, a qualitative analysis was carried out by means of electron microscopy. Results: No significant differences were found between the bacterial growth profiles of 4xHt graft and BPTB graft in microcalorimetry and colony counting. In the samples analyzed with electron microscopy, no specific biofilm growth pattern was identified upon comparing BPTB graft to 4xHt graft. Conclusions: There were no significant differences at either the quantitative or qualitative level when comparing bacterial growth in BPTB graft to that in 4xHt graft. Therefore, the presence of sutures in 4xHt graft cannot be established as a predisposing factor for increased biofilm growth in this in vitro study.

: Background: Pseudomonas aeruginosa is an opportunistic pathogen involved in number of hospital acquired infections such as catheter-associated urinary tract infections, bacteremia, septicemia, skin infections and ventilator-associated pneumoniae. Biofilm formation is an important trait implicated in chronic infections, such as cystic fibrosis and chromic pulmonary obstruction. Method: A total of 266 isolates were collected from the Armed Forces Institute of Pathology (AFIP). Antibiotic susceptibility was assessed by double disk synergy testing. ESBL and Modified Hodge testing was performed for phenotypic confirmation of carbapenemases. Molecular screening of the genes was done by PCR. Micro-dilution broth method was used to determine minimum inhibitory concentrations of antibiotics. Biofilm formation was done by micro-titer plate assay. Results: Overall, 20% of the P. aeruginosa isolates were extensively drug resistant (XDR-PA) and 25% were multi-drug-resistant (MDR-PA). Likewise, 43% of the isolates were ESBL producers and carbapenemase production was detected in 40% of the isolates. Molecular analysis confirmed occurrence of different resistant factors in ESBL positive isolates; 67% carried bla-TEM, 62% bla-CTXM-15, 41% bla-SHV, 34% bla-CTXM-14 and 33% bla-OXA-1. In addition, 68% of carbapenem-resistant isolates were positive for bla-NDM-1, 25% for bla-OXA-48 and 22% for bla-KPC-2. Biofilm formation was tested for 234 isolates, out of which 28% were strong biofilm formers. Moderate and weak biofilm formers were 46% and 23% respectively. Overall, ciprofloxacin, levofloxacin and cefepime showed inhibitory effects on P. aeruginosa biofilms. Antibiotics in combination showed strong synergistic effects (ciprofloxacin &amp; cefepime); while gentamicin and cefepime resulted into complete eradication of P. aeruginosa biofilm. Conclusion: We confirm strong synergistic effects of gentamicin and cefepime that completely eradicated P. aeruginosa biofilm. We further confirm inhibitory effects of ciprofloxacin, levofloxacin and cefepime on P. aeruginosa biofilms.

Staphylococci sp. have become the primary pathogens implicated in infective endocarditis, especially within high-income nations. This along with the increasing burden of healthcare, aging populations and the protracted course the infections may take, contribute to a significant challenge for healthcare systems. A systematic review was conducted using relevant search criteria from PubMed, Ovid’s version of MEDLINE, and EMBASE, and data were tabulated from randomized controlled trials (RCT), observational cohort studies, meta-analysis, and basic research articles. The review was registered with the OSF register of systematic reviews and followed the PRISMA reporting guidelines. 35 studies met the inclusion criteria and were included in the final systematic review. The role of Staphylococcus aureus and its interaction with the protective shield and host protection functions was identified and highlighted in several studies. The interaction between infective endocarditis pathogens, vascular endothelium, and blood constituents was also explored giving rise to the potential use of antiplatelets as preventative and/or curative agents. Several factors allow Staphylococcus aureus infections to proliferate within the host with numerous promoting and perpetuating agents. The complex interaction with the hosts' innate immunity also potentiates its virulence. Ameliorating these molecular pathways may serve as a therapeutic avenue for the prevention and treatment of these infections in near future.

Even after debridement and chemical root canal preparation, multispecies bacterial biofilms can still be found in root canals and dentinal tubules. This demonstrates the necessity of using suitable antibacterial endodontic sealers. Due to their well-known biological qualities, calcium silicate based root canal sealers or “bioceramic’ sealers have recently been launched and can be successful in endodontic procedures. This study's objective was to compare the impact of CerasealR, Total Fill BC SealerR, Bio-C SealerR, AH Plus BioceramicR, K-biocerR and SealiteR on the elimination of a multispecies’ endodontic biofilm at 3, 7 and 14 days. Enterococcus faecalis, Pseudomonas Aeruginosa, Candida Albicans and Proteus Mirabilis were cultured on specific agars and later grown in Brain Heart Infusion broth on hydroxyapatite discs pretreated with collagen type 1 and incubated for 18 days. The resulting biofilm was then placed on a 10mm round shaped blotting paper set on a metallic net in a 6cm petri dish with an orthodontic bend filled with the calcium silicate based root canal sealer in direct contact with the biofilm. In all tested groups, the total bacterial count has significantly decreased between day 3 and day 14 (P<0.05) with no statistically significant differences among the different sealers’ groups at all time points. Sealite group was capable of decreasing the Candida Albicans count significantly between day 3 and day 14 (P<0.05) in comparison with the bioceramic groups. All sealers had antibacterial activity against the multispecies biofilm between day 3 and day 14.

Metformin (MeT) is an FDA-approved drug with a myriad of health benefits. Besides being used as an anti-diabetic drug, MeT is also effective against various cancers, liver-, cardiovascular-, and renal diseases. It has also been proven to demonstrate anti-ageing and neuroprotective effects. This study was undertaken to examine its unique potential as an anti-virulence drug against an opportunistic bacterial pathogen, Pseudomonas aeruginosa. Due to the menace of multidrug resistance in pathogenic microorganisms, many novel or repurposed drugs with anti-virulence prospects are emerging as next-generation therapies with the aim to overshadow the application of existing antimicrobial regimens. The quorum sensing (QS) mechanisms of P. aeruginosa are an attractive drug target for attenuating bacterial virulence. In this context, the anti-QS potential of MeT was scrutinized using biosensor assays. MeT was comprehensively evaluated for its effects on different motility phenotypes, virulence factor production (phenotypic and genotypic expression) along with biofilm development in P. aeruginosa in vitro. At sub-lethal concentrations, MeT displayed prolific quorum quenching (QQ) ability and remarkably inhibited AHL biosynthesis in P. aeruginosa. Moreover, MeT (1/8 MIC) effectively downregulated the expression levels of various QS- and virulence genes in P. aeruginosa, which coincided with a notable reduction in the levels of alginate, hemolysin, pyocyanin, pyochelin, elastase, and protease production. In silico analysis through molecular docking also predicted strong associations between the QS receptors of P. aeruginosa and MeT. MeT also compromised the motility phenotypes and successfully abrogated biofilm formation by inhibiting EPS production in P. aeruginosa. Hence, the QQ, anti-virulence, and anti-fouling potential of MeT was elucidated for the first time against P. aeruginosa.

Objective. Whether a minimum quantity of saliva is needed to inhibit the caries process is unclear. Here, we evaluated the effect of saliva dilutions on an in vitro caries model with Streptococcus mutans (S. mutans) biofilms. Methods. S. mutans biofilms were grown on enamel and root dentin slabs, in culture media containing different proportions of saliva (v/v): 0%, 5%, 10%, 25%, 50%, 75% and 100% saliva, and exposed to a 10% sucrose solution (5 min, 3x/day), with appropriate controls. After 5 (enamel) and 4 (dentin) days, demineralization, biomass, viable bacteria and polysaccharide formation were analyzed. The acidogenicity of the spent media was monitored overtime. Assays were carried out in triplicate in 2 independent experiments (n=6). Results. An inverse relationship was observed between acidogenicity, demineralization, and saliva proportion, both in enamel and dentin. A marked reduction in enamel and dentin demineralization was observed when small amounts of saliva were incorporated in the medium. For both tissues, a significant reduction in biomass, viable S. mutans cells and polysaccharides were observed when saliva was present, in a concentration-dependent manner. Conclusions. High quantities of saliva can almost completely inhibit sucrose-induced cariogenicity, but small amounts can also exert a dose-dependent caries-protective effect.

Biofilm is a complex community of microorganisms that are attached to surfaces and encased in a self-produced extracellular matrix. Machine learning (ML) techniques have been applied to various aspects of biofilm research, such as predicting biofilm formation, identifying key genes, and designing new therapeutic strategies. In this study, we conducted a bibliometric analysis of machine learning in biofilm research to provide a comprehensive overview of the current state of the field. We searched the Web of Science database for articles published included "machine learning biofilm". A total of 126 articles were identified and analysed. Our results showed that the number of publications on machine learning in biofilm has been increasing rapidly over the past decade, indicating a growing interest in the application of ML techniques to biofilm research. The analysis also revealed that the most common research topics in this area were related to biofilm formation, prediction, and control. Furthermore, the most frequently used ML techniques in biofilm research were artificial neural networks and support vector machines. Overall, our study provides valuable insights into the current trends and future directions of machine learning in biofilm research. It also highlights the importance of interdisciplinary collaboration between biofilm researchers and ML experts to drive innovation in this field.

Myrtus communis L., commonly known as true myrtle, is a medicinal plant native to the Mediterranean area. Since ancient times inhabitants of this area have been using it for its cultural and medicinal properties. Due to the high content of essential oil in its flowers, leaves and fruits, M. communis is an important medicinal and aromatic species from Myrtaceae family. Because of the presence of vast diversity of biomolecules in its aerial parts, it exhibits several biological properties of antioxidant, antimicrobial and anticancer. There has been increasing scientific interest in the field to understand the pleotropic effects of its extracts or essential oils on various ailments and diseases. This purpose of this review is to summarizes the chemical composition, traditional uses, and biological activities of M. communis L. leaves documented in numerous recent studies.

In cystic fibrosis (CF), pulmonary infection with Pseudomonas aeruginosa is a cause of increased morbidity and mortality, especially in patients for whom infection becomes chronic and there is reliance on long-term suppressive therapies. Current antimicrobials, though varied mechanistically and by mode of delivery, are inadequate not only due to eradication failure in many cases, but also because they do not halt the progression of lung function decline over time. One of the reasons for this failure is thought to be the biofilm mode of growth of P. aeruginosa, wherein self-secreted exopolysaccharides (EPSs) provide physical protection against antibiotics and an array of niches with resulting metabolic and phenotypic heterogeneity. Targeting the three EPSs secreted by P. aeruginosa (alginate, Psl and Pel) is currently under investigation as a way of disrupting the biofilm extracellular matrix to potentiate the action of antibiotics. In this review, we look at each EPS as a potential therapeutic target for combatting pulmonary infection with P. aeruginosa in CF, with a particular focus on the current evidence for these emerging therapies and barriers to bringing these therapies into clinic.

In this review, we present several extracellular proteases, enzymes, membrane permeases, and transporters as essential accessories proteins for nutrient assimilation, conservation, and transportation as determined by nutrient repletion or depletion. As an obligate aerobic pathogen, it is crucial for invading Cryptococcus (C.) neoformans to negotiate its adaptation to human internal organs like the brain and spinal cord, where the oxygen level is low compared to peripheral organs. Besides, essential metals like copper and iron are important cofactors to functional proteins; however, these metals are not usually freely available to invading human pathogens. Again, the phagolysosome low pH with glucose paucity, internal temperature, immune response, and complex extracellular matrixes are challenging environments that must be circumvented by C. neoformans in the systemic tissues for survival, adaptation, and infection in humans. We review extensive works on several extracellular proteases, enzymes, membrane permeases and transporters orchestrated by different transcription factors and present these proteins as weapons needed to outwit systemic resistance to invading pathogens. Lastly, we examine the extracellular secretory vesicles of C. neoformans as “an exosomal virulence bag” that harbours urease, laccase, phosphatase, and capsular components as additional secretory weapons for tissue invasion and persistence.

The choice of antibiotic regimens to use in patients presenting with diabetic foot osteomyelitis and their duration differs according to the situation. Antibiotics play a more important role in the medical option where no infected bone has been resected while their role is reduced but not negligible in the case of surgical options. Some studies have reported the presence of biofilm structures in bone samples taken from patients with diabetic foot osteomyelitis which raises the question of the place of anti-biofilm antibiotic regimens in this setting. During the last two decades, clinical studies have suggested a potential benefit for anti-biofilm antibiotics, mainly rifampicin against staphylococci and fluoroquinolones against gram-negative bacilli. No data from randomized controlled studies have however been reported so far. The present work provides a summary of the available data on the question of the place of anti-biofilm antibiotics for the treatment of diabetic foot osteomyelitis but also the potential limitations of such treatments.

Staphylococci sp. have become the primary pathogens implicated in infective endocarditis, especially within high-income nations. Coupled with the increasing burden of healthcare with aging populations and the protracted course the infections may take, these infections contribute to a significant challenge for healthcare. A systematic review was conducted using relevant search criteria from PubMed, Ovid’s version of MEDLINE, and EMBASE, and data were tabulated from randomized controlled trials (RCT), observational cohort studies, meta-analysis, and basic research articles. The review was registered with the OSF register of systematic reviews and followed the PRISMA reporting guidelines. 35 studies met the inclusion criteria and were included in the final systematic review. The role of Staphylococcus aureus and its interaction with the protective shield and host protection functions is identified and highlighted in several studies. The interaction between infective endocarditis pathogens, vascular endothelium, and blood constituents is also explored giving rise to the potential use of antiplatelets as preventative and/or curative agents. Several factors allow Staphylococcus aureus infections to proliferate within the host with numerous promoting and perpetuating agents. The complex interaction with the hosts' innate immunity also potentiates its virulence. Ameliorating these molecular pathways may serve as a therapeutic avenue for the prevention and treatment of these infections in the near future.

Staphylococcus aureus is a microorganism frequently associated with implant-related infections, owing to its ability to produce biofilms. These infections are difficult to treat because antimicrobials must cross the biofilm to effectively inhibit bacterial growth. Although some antibiotics can penetrate the biofilm and reduce the bacterial load, it is important to understand that the results of routine sensitivity tests are not always valid for interpreting the activity of different drugs. In this review, a broad discussion on the genes involved in biofilm formation, quorum sensing, and antimicrobial activity in monotherapy and combination therapy is presented that should benefit researchers engaged in optimizing the treatment of infections associated with S. aureus biofilms.

Lyme disease (LD) is a tick-transmitted infection caused by Borrelia burgdorferi sensu lato species which includes B. burgdorferi, B. afzelii, and B. garinii. The majority of patients with early LD can be cured by standard treatment, yet some still suffer from post-treatment Lyme disease syndrome (PTLDS). The presence of Borrelia persisters has been proposed as a contributing factor, which cannnot be completely killed by the currently used antibiotics for Lyme disease. Finding new pharmaceuticals targeting Borrelia persisters is crucial in developing more effective treatment. Here, we first confirmed the existence of persisters in cultures of B. garinii and B. afzelii and then conducted high-throughput screening of a custom drug library against persister-rich stationary-phase cultures of B. garinii and B. afzelii. Among 2427 compounds screened, hypocrellin A (HA), anthracycline class of drugs, and topical antibiotics along with some other natural compounds were identified to have strong potential in killing persisters of B. garinii and B. afzelii. HA was the most active anti-Borrelia compound, capable of eradicating stationary-phase Borrelia persisters, in particular when combined with doxycycline and/or ceftriaxone. Liposoluble antioxidant vitamin E was found to antagonize the activity of HA, indicating HA’s target is the cell membrane where HA-triggered reactive oxygen species (ROS) generation took place in the presence of light. HA was found to have distinct bactericidal activity against Borrelia species but had poor or no activity against Gram-positive and Gram-negative bacteria. Identification of the above-mentioned drug candidates may help to develop more effective therapies for LD.

Antifungal agents are not always efficient in resolving vulvovaginal candidiasis (VVC), a common genital infection caused by overgrowth of Candida spp., including Candida albicans, or preventing recurrent infections. Although lactobacilli (which are dominant microorganisms constituting healthy human vaginal microbiota) are important barriers against VVC, the Lactobacillus metabolite concentration needed to suppress VVC is unknown. Therefore, we quantitatively evaluated Lactobacillus metabolite concentrations to determine their effect on Candida spp., including 27 vaginal strains of Lactobacillus crispatus, Lactobacillus jensenii, Lactobacillus gasseri, Lacticaseibacillus rhamnosus, and Limosilactobacillus vaginalis, with inhibitory abilities against biofilms of Candida clinical isolates. Lactobacillus culture supernatants suppressed viable bacteria by approximately 24%-92% relative to preformed Candida biofilms, but their suppression differed between strains, not species. Lactate production was necessary to suppress preformed biofilms and hyphal elongation of C. albicans, whereas hydrogen peroxide was not always essential. Both lactic acid and hydrogen peroxide were required to suppress Candida planktonic cell growth. Lactobacillus strains that significantly inhibited biofilm formation in culture supernatant also inhibited Candida adhesion to epithelial cells in an actual live bacterial adhesion competition test. Healthy human microflora and their metabolites may play important roles in the development of new antifungal agent against VVC caused by C. albicans.

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).

Use of rhizosphere microorganisms provides an alternative or supplement to conventional plant breeding to improve water deficit tolerance of tomato plants. Experiment was carried out to explore the effect of two microbial species, AMF (Rhizophagus irregularis) and Bacillus subtilis, in single and co-application, on growth, colonization, and molecular aspects of tomato plants under drought stress. Co-inoculated plants showed less reduction in growth traits, photosynthetic pigments, colonization rate, and increased compatible solutes like proline which help in sustaining relative water content than non-inoculated plants. Inoculation considerably enhanced proline dehydrogenase activity, and significantly reduced both Δ1-pyrroline-5-carboxylate reductase Δ1-pyrroline-5-carboxylate synthetase activity causing lower proline accumulation in inoculated plants under drought stress. Co-inoculated plants showed obvious upregulation of antioxidant system, thus facilitating amelioration of oxidative stress through exclusion of reactive oxygen species. No inoculation under drought stress upregulated abscisic acid related genes expression but have no effect in plants inoculated either sole or mixed inoculation. Expression of aquaporin genes was upregulated in plants co-inoculated and with AMF alone under normal condition. However the expression of aquaporin genes were decreased or unaffected in plants inoculated with Bacillus subtilis but increased in non-inoculated plants. Co-applied AMF and bacillus subtilis substantially increase drought tolerance by upregulating proline metabolism, antioxidant enzymes and aquaporin genes. Therefore our results suggest that co-inoculation mediated drought tolerance is linked with increased proline accumulation, enhanced antioxidant enzyme activities and differential regulation of ABA biosynthetic and aquaporin genes, which is vital for osmotic adjustment of host plant.

Biofilm formation is important in the free-living and symbiotic lifestyles of Sinorhizobium meliloti. Here we show that the S. meliloti NspS-MbaA system is homologous to the c-di-GMP modulating NspS-MbaA system described in Vibrio cholerae and modulates biofilm formation, exopolysaccharide (EPS) production and motility in S. meliloti in response to exogenous polyamines. Biofilm and EPS production in quorum sensing-deficient wild type strain 1021 decreased in cultures containing putrescine, 1,3-diaminopropane or spermine, but were unaffected in a 1021 nspS mutant (1021 nspS). Decreases in biofilm formation caused by these polyamines paralleled decreases in EPS production and increases in nspS transcription. Cell aggregation did not differ markedly between strain 1021 and 1021 nspS. The S. meliloti quorum sensing-proficient Rm8530 wild type strain and nspS mutant (Rm8530 nspS) produced similar levels of biofilm under control conditions and 3.2- and 2.2-fold more biofilm in cultures with norspermidine, but these changes did not correlate with EPS production. Rm8530 nspS aggregated up to several fold more than the wild type under most conditions. Changes caused by polyamines in swimming and swarming motility were not generally dependent on NspS-MbaA in either 1021 or Rm8530. We speculate that the S. meliloti NspS-MbaA system could modulate biofilm formation in response to environmental polyamines.

Infective endocarditis remains an illness that carries a significant burden to healthcare resources. In recent times, there has been a shift from Streptococcus sp to Staphylococcus sp as the primary organism of interest. This has significant consequences given the virulence of Staphylococcus and its propensity to form a biofilm, rendering non-surgical therapy ineffective. In addition, antibiotic resistance has affected treatment of this organism. The cohorts at most risk for Staphylococcal endocarditis are the elderly patients with multiple comorbidities. The innovation of transcatheter technologies alongside other cardiac interventions such as implantable devices have contributed to the increased risk attributable to this cohort. We examine the role of the heart team for diagnosis and treatment of this condition. In addition, we examine the determinants of virulence of Staphylococcus aureus, the interaction with hosts immunity and the discovery and emergence of a potential vaccine. We also examine the potential role of prophylactic antibiotics during dental procedures. With increasing rates of transcatheter device implantations, there is a projected increment of endocarditis especially in this high-risk group. A high index of suspicion is needed alongside early initiation of therapy and referral to the heart time to improve outcomes.

ExuR and UxuR are paralogous proteins belonging to the GntR family of transcriptional regulators. Both are known to control hexuronic acid metabolism in a variety of Gammaproteobacteria but the relative impact of each of them is still unclear. Here, we apply 2D difference electrophoresis followed by mass-spectrometry to characterise the changes in the Escherichia coli proteome in response to the uxuR or exuR deletion. Our data clearly show that the effects are different: deletion of uxuR resulted in significantly enhanced expression of D-mannonate dehydratase UxuA and flagellar protein FliC, and inhibition of outer membrane porin OmpF, while the absence of ExuR did not significantly alter the spectrum of detected proteins.This suggests that the roles of proteins predicted as homologs are far from identical. Effects of uxuR deletion were largely dependent on the cultivation conditions: during growth with glucose, UxuA and FliC were dramatically altered, while during growth with glucuronate activation of both was not so prominent. During growth on glucose, the maximal activation was detected for FliC. This was further confirmed by expression analysis and physiological tests thus suggesting involvement of UxuR in the regulation of bacterial motility and biofilm formation.

The biofilm is a conglomerate of cells surrounded by an extracellular matrix, which contributes to the persistence of infections. The difficulty in removing the biofilm drives the research for new therapeutic options. In this work, the effect of terpenes (-)-trans-Caryophyllene, (S)-cis-Verbenol, (S)-(-)-Limonene, (R)-(+)-Limonene, and linalool was evaluated, individually and in combinations on bacterial growth, by assay with resazurin; the formation of biofilm, by assay with violet crystal; and the expression of associated genes, by real-time PCR, in two clinical isolates of S. aureus, ST30-t019 and ST5-t311, responsible for more than 90% of pediatric infections by this pathogen in Paraguay. All combinations of terpenes can inhibit biofilm formation in more than 50% without affecting bacterial growth. The most effective combination was (-)-trans-Caryophyllene and linalool at a 500 μg/mL concentration for each, with an inhibition percentage of 88%. This combination decreased the expression levels of the sdrD, spa, agr, and hld genes associated with the initial cell adhesion stage and quorum sensing. At the same time, it increased the expression levels of the cap5B and cap5C genes related to the production of capsular polysaccharides. The combinations of compounds tested are promising alternatives to inhibit biofilm formation in S. aureus.