Presence Of Biofilm Research Articles

NIR‐II emissive biohybrid nanovesicles as mild‐temperature photothermal antibiofilm agents against acute bacterial skin and skin‐structure infections

AbstractThe emergence of antibiotic‐resistant bacteria poses a significant challenge to the prompt and appropriate treatment of pathogenic bacteria infections, such as acute bacterial skin and skin‐structure infections (ABSSSI), especially in the presence of biofilms. Bacterial biofilms are naturally resistant to antibiotics and the human immune system, making biofilm‐based infections extremely difficult to treat. Therefore, developing new antibacterial therapies targeting biofilms is crucial. Aggregation‐induced emission luminogens with fluorescence in the second near‐infrared window (NIR‐II AIEgens), which can be activated by a near‐infrared laser to generate heat, offer an effective and precise photothermal therapy (PTT) approach for treating deep‐tissue bacterial infections. However, the presence of biofilms impedes the entry of photosensitizers into the infected area, requiring higher drug doses and increasing the risk of PTT. Herein, we developed a biocompatible AIEgen‐based biohybrid nano formulation that incorporates the BPBBT (NIR‐II AIEgen) and antibiofilm α‐amylase into a red blood cell (RBC) membrane‐derived nanovesicle carrier for a PTT/biofilm degradation combination therapy. The synergistic effect of this new formulation enhances both the photothermal capability of BPBBT and the biofilm degradation compared to traditional individual treatments. The new combination therapy demonstrated significant improvement in treating severe Staphylococcus aureus infections caused by biofilms in vitro and in vivo, presenting a promising alternative to traditional antibiotic therapy.

Assessing the reproductive potential and development of the tropical short-spined white sea urchin, Salmacis sphaeroides (Linnaeus, 1758)

ABSTRACT Previous studies have achieved success in obtaining cultured juveniles of the sea urchin Salmacis sphaeroides, but few have reported their reproduction potential and development rates. This comprehensive study examined the spawning potential of broodstock and described embryonic, larval and juvenile development. The broodstock consisted of wild-caught specimens from Singapore’s coastal waters that were regularly provided a mixed animal-plant diet comprising 3 g prawn and 3 g corn. Gametes were obtained using 0.5 M of potassium chloride (KCl) injection into the coelomic cavity. Fertilization rates of the 32 spawning attempts varied from 42.9% to 100%. Hatched larvae were subsequently reared with a density of 0.5 larvae ml−1 in 50 µm filtered seawater at 28°C and fed 20,000 cells ml−1 of Tisochrysis lutea once every 2 days. Despite the presence of natural biofilms as settlement cues, the settlement rates in culture were very low and variable (2.08–9.78%). The majority of juvenile S. sphaeroides from F1 and F2 generations was sexually mature at ≥35 mm in test diameter, and the sex ratios were female-biased, ranging from 1:1.14 to 1:8. Findings from this study open up new opportunities for developing tropical sea urchin cultures under controlled rearing systems that can guarantee production.

Enhanced degradation of polyethylene terephthalate (PET) microplastics by an engineered Stenotrophomonas pavanii in the presence of biofilm

Polyethylene terephthalate (PET) microplastics pose significant environmental and human health risks due to their resistance to degradation and accumulation in ecosystems. In this study, we engineered Stenotrophomonas pavanii JWG-G1, a robust biofilm-forming bacterium, to overexpress the PET hydrolase (DuraPETase) for PET microplastics degradation at ambient temperature. Nine endogenous PET hydrolases were identified through genome sequencing of S. pavanii, and were successfully expressed in Escherichia coli BL21(DE3). Among them, hydrolase Est_B achieved 100% degradation of bis(2-hydroxyethyl) terephthalate (BHET) at an initial concentration of 0.23 mg/mL at 30 °C within 4 h, identifying it as a novel BHETase. However, the PET degradation performance of all endogenous PET hydrolases was inferior to that of DuraPETase. The engineered strain overexpressing DuraPETase demonstrated a significant enhancement in PET degradation, achieving a 38.04 μM total product release of high-crystallinity PET microplastics after 30 days at 30 °C. The degradation extent was greater than that of low biofilm-forming engineered strains, attributing to the aggregation of DuraPETase on the PET surface in the presence of biofilm. Additionally, this engineered strain also maintained PET degradation activity across various water environments and demonstrated effectiveness in degrading other polyester plastics. This is the first report demonstrating that an engineered strain of Stenotrophomonas species is capable of simultaneously secreting exogenous hydrolase and degrading polyester microplastics, representing a novel approach in the development of engineered bacteria with potential applications in bioreactor systems and environmental remediation.

Association of biofilm and microbial metrics with healing rate in older adults with chronic venous leg ulcers.

The presence of microbial biofilms in many human chronic wounds led to the hypothesis that biofilms delay healing of these wounds. We tested this hypothesis in a population of 117 older individuals with venous leg ulcers who were receiving standardised therapy, including frequent debridement. Debridement specimens were analysed for the amount of bacterial biomass by two independent methods: a microscopic approach that scored the relative size and number of bacterial aggregates, interpreted as a biofilm metric, and conventional enumeration by agar plating for viable bacteria. The plating protocol yielded three distinct values: the total viable bacterial count, bleach-tolerant bacteria, and the log reduction in viable bacteria upon bleach treatment. Wound healing rates over an 8-week observation period were calculated as the rate of decrease of the equivalent diameter of the wound. There was no statistically significant association between wound healing and the biofilm metric in any of the three analyses performed (p ≥0.15). In all three statistical tests, wound healing was associated with the log reduction caused by bleach treatment (p ≤0.004); wounds that harboured bacteria that were more bleach-susceptible healed more slowly. A refinement of the model of chronic wound infection pathogenesis is proposed in which dormant bacteria constitute a persistent nidus and outgrowth of metabolically active cells impairs healing. This model constitutes a new hypothesis as metabolic activity was not directly measured in this investigation.

Biofilms and microbiome profiles in chronic wounds: links to antibiotic use and wound severity in a Sri Lankan cohort.

We have characterized the microbiome of infected chronic diabetic wounds (CDWs), exploring associations with antibiotic use and wound severity in a Sri Lankan cohort. Fifty CDW patients were enrolled, 38 of whom received antibiotics. Tissue biopsies were analysed by microbiome profiling, and wounds were graded using the University of Texas Wound Grading System. Biofilm presence was assessed in 20 wounds. The microbiome was largely dominated by Enterobacteriaceae, Pseudomonadaceae, Streptococcaceae, and Corynebacteriaceae. Proteobacteria levels were significantly higher in antibiotic-treated wounds (P=.019), with increased Pseudomonas abundance. Wounds were categorized as grade 1 (10), grade 2 (29), and grade 3 (11). Alpha diversity varied by wound grade (P=.015), with grade 2 wounds showing the highest diversity and grade 3 the lowest. All 20 tested wounds were biofilm-positive, and community composition varied more in antibiotic-treated wounds (P=.004). CDW microbiomes were dominated by Enterobacteriaceae and Pseudomonadaceae, with elevated Proteobacteria in antibiotic-treated wounds. Alpha diversity correlated with wound severity, peaking in grade 2 wounds. The high prevalence of biofilms in wounds underscores the need for management of CDWs that address microbial complexity.

ISOLATION AND CHARACTERIZATION OF BIOFILM FORMING ESCHERICHIA COLI FROM CHICKEN MEAT SAMPLES

The present study was aimed to investigate the presence of Escherichia coli (E.coli) in raw chicken meat samples collected from retail shops, as well as the biofilm-forming ability of field isolates, and to characterize different adhesion genes. Out of 20 chicken meat samples, 17 (85%) were positive for E. coli. Fifteen E. coli strains were characterized by PCR using the 16S rDNA primers and all the isolates were positive which confirmed that all the isolates were E.coli. Out of the 15 confirmed E.coli field isolates which were subjected to biofilm-forming assay, 46% of them were found to be strong biofilm producers. While all the isolates were screened for the presence of adhesion genes viz. luxS, csgA, fimH, fimA, and papC, the adhesion gene luxS was detected in all the strains (100%). The other adhesion genes csgA, fimH and fimA were detected in 93%, 93%, and 73% of the isolates, respectively. The E. coli field isolates were screened blaTEM gene was detected in only four strains, which was categorized under strong biofilm producers. This study demonstrated the presence of biofilm forming E. coli in the raw chicken meat samples as contaminants, causing spoilage and potentially posing risk to consumer’s health and safety.

Attached and suspended biomass kinetics in an IFAS-MBR system operated under intermittent aeration: Long-term monitoring under SRT variation

This study thoroughly investigates a Membrane BioReactor – Integrated Fixed Film Activated Sludge – Intermittent Aeration (MBR-IFAS-IA) pilot plant operated from a biokinetic point of view. Specifically, respirometric techniques were applied on suspended and attached biomass to evaluate kinetic and stoichiometric parameters. The main aim was to investigate how the simultaneous presence of biofilm and activated sludge could affect the kinetic behaviour and the role of the Sludge Retention Time (SRT) variation in the kinetic behaviour of the system. The results highlighted a mutual interaction between suspended biomass and biofilm in the IFAS-MBR configuration. In Period I both the heterotrophic yield and growth rate of suspended biomass were higher compared to that of biofilm, thus highlighting higher affinity with organic matter; in contrast, the biofilm showed high affinity with nitrification, with increased nitrification rates with decreasing SRT and sustaining nitrification in the activated sludge due to “seeding” effect. Therefore, the suggestion is that it is possible to operate IFAS-MBR systems at low SRT without hampering the nitrification ability due to the growth of nitrifiers in the biofilm. Respirometry has been confirmed to be an effective tool for evaluating biomass kinetic and stoichiometric parameters. The results of this study highlighted the effect of IFAS configuration and can help apply mathematical models in the design phase and monitor biomass viability during plant operations.

Biofilm infections of endobronchial valves in COPD patients after endoscopic lung volume reduction: a pilot study with FISHseq

Endoscopic lung volume reduction (ELVR) using endobronchial valves (EBV) is a treatment option for a subset of patients with severe chronic obstructive pulmonary disease (COPD), suffering from emphysema and hyperinflation. In this pilot study, we aimed to determine the presence of bacterial biofilm infections on EBV and investigate their involvement in lack of clinical benefits, worsening symptomatology, and increased exacerbations that lead to the decision to remove EBVs. We analyzed ten COPD patients with ELVR who underwent EBV removal. Clinical data were compared to the microbiological findings from conventional EBV culture. In addition, EBV were analyzed by FISHseq, a combination of Fluorescence in situ hybridization (FISH) with PCR and sequencing, for visualization and identification of microorganisms and biofilms. All ten patients presented with clinical symptoms, including pneumonia and recurrent exacerbations. Microbiological cultures from EBV detected several microorganisms in all ten patients. FISHseq showed either mixed or monospecies colonization on the EBV, including oropharyngeal bacterial flora, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus spp., and Fusobacterium sp. On 5/10 EBV, FISHseq visualized biofilms, on 1/10 microbial microcolonies, on 3/10 single microorganisms, and on 1/10 no microorganisms. The results of the study demonstrate the presence of biofilms on EBV for the first time and its potential involvement in increased exacerbations and clinical worsening in patients with ELVR. However, further prospective studies are needed to evaluate the clinical relevance of biofilm formation on EBV and appropriate treatment options to avoid infections in patients with ELVR.

Emerging strategies for treating medical device and wound-associated biofilm infections.

Bacterial infections represent a significant global threat to human health, leading to considerable economic losses through increased healthcare costs and reduced productivity. One major challenge in treating these infections is the presence of biofilms - structured bacterial communities that form protective barriers, making traditional treatments less effective. Additionally, the rise of antibiotic-resistant bacteria has exacerbated treatment difficulties. To address these challenges, researchers are developing and exploring innovative approaches to combat biofilm-related infections. This mini-review highlights recent advancements in the following key areas: surface anti-adhesion technologies, electricity, photo/acoustic-active materials, endogenous mimicking agents, and innovative drug delivery systems. These strategies aim to prevent biofilm formation, disrupt existing biofilms, and enhance the efficacy of antimicrobial treatments. Currently, these approaches show great potential for applications in medical fields such as medical device and wound - associated biofilm infections. By summarizing these developments, this mini-review provides a comprehensive resource for researchers seeking to advance the management and treatment of biofilm-associated infections.

Microbial degradation of the waste jute fiber and sawdust fiber-based epoxy composites in drainage system

The non-biodegradable nature of polymers presents a considerable environmental hazard, mainly when they accumulate in drainage systems and pollute the water. The application of natural fiber composites has the potential to offer a feasible resolution to address this problem, as natural fibers possess inherent biodegradability. This study examined the degradation ability of epoxy composites made with 5 wt% waste jute fiber and 5 wt% waste sawdust fiber when subjected to drainage water for one year. The composites comprising jute fiber and sawdust demonstrated a reduction in tensile strength by 57 % and 40 %, respectively, because of biodegradation caused by microorganisms. The microorganism consumed the fiber for energy, resulting in significant weight and flexural strength loss. The weathered waste jute and sawdust fiber composite samples displayed an additional peak at a wavenumber of 1700 cm−1 for FTIR analysis, indicating the presence of the C=O group and reflecting CO2 production. The SEM image reveals the presence of clusters, biofilms, and colonies of microorganisms on the surface of the composites, indicating that the microbes were utilizing the fibers and matrix as a substrate for growth and multiplication. This research contributes to the understanding of the degradation mechanisms of sustainable composites and provides insight into the advancement of eco-friendly materials to reduce water pollution.

Essential Oils of Some Potential Medicinal Plants and their Wound Healing Activities.

The wound has been recognised as a deep cut or tearing of the epidermis, which is also referred to as trauma and harm to the body tissues. Healing of wounds requires a coordinated series of cellular processes, including cell attraction, proliferation, differentiation, and angiogenesis. These processes involve interactions between various cells, such as macrophages, endothelial cells, keratinocytes, fibroblasts, growth hormones, and proteases. The outcome of wounds can be fatal if not treated properly, resulting in chronic wounds, chronic pain, and even death. Wound healing is replacing missing tissue with tissue repairs and regeneration. Some local variables are the presence of tissue maceration, foreign objects, biofilm, hypoxia, ischemia, and wound infection. Sustained growth factor delivery, siRNA delivery, micro-RNA targeting, and stem cell therapy are all emerging possible therapeutic approaches for wound healing. Traditional approaches, such as Ayurveda, Siddha, and Unani medicines, are also being used for treatment. The therapeutic application of nanoformulations in wound infections has shown various beneficial effects. Several herbal medicines, especially essential oils have shown potential wound healing activities, such as lavender, tea tree, sesame, olive, etc. Various nanoparticles and their nanoformulations have been explored in wound healing therapy. The present review article highlights several aspects of essential oils for wound healing activity through a novel drug delivery system. Further, some patents on wound healing through herbal medicine have been listed.

A pH-modulated polymeric drug-release system simultaneously combats biofilms and planktonic bacteria to eliminate bacterial biofilm

Bacterial infection, leading to biofilm formation, raises grave concerns. With the aim of eliminating both integrity of biofilms and individual bacterial cells, it is desirable to develop bacterial biofilm-eliminating material to be combined with dispersal and anti-microbial agents. Herein, a biofilm-eliminating enzyme (α amylase) was incorporated in novel pH-sensitive polymer hydrogel, Poly (methacrylic acid-co-2-(dimethylamino)ethyl methacrylate), which encapsulates drug-loaded porous Zeolitic Imidazolate Framework-8 (ZIF-8). At body temperature (37 °C) the maximum swelling of the hydrogel was observed at pH 8.5, which assisted in rupturing biofilm by releasing α amylase. Amylase, encapsulated in polymer matrix reached 90% release after 6 days at 8.5, while CIP was released 96% on day 23 at pH 8.5. The antibiofilm activity of drug-releasing system was assessed against E. coli and S. aureus. The overall bacterial viability of biofilms showed significant time-dependent declines, when exposed to drug-loaded hydrogel. Importantly, cytotoxicity experiments showed excellent biocompatibility of hydrogel. In the in vivo deep wound infection model, drug-loaded hydrogel treatment showed complete wound closure with proper tissue regeneration. No inflammatory, or systemic toxicity of hydrogel was observed. The drug release from hydrogel is initiated only upon receiving physiological cue arising due to biofilm formation. Therefore, this hydrogel serves as reservoir for antibacterial drug, which release it only in presence of biofilm and thus work for sustained release for long period, compared to conventional drug loaded films or coatings. A powerful modality for management of biofilm-associated infections can be provided by the proposed synergistic strategy for complete elimination of biofilms.

Cellulase exhibited a therapeutic potential to inhibit Salmonella enterica serovar Typhi biofilm by targeting multiple regulatory proteins of biofilm

Biofilm-mediated Salmonella enterica serovar Typhi (Salmonella Ser. Typhi) infections are a growing global health issue due to the formation of antibiotic resistance. The study aimed to discover some of the druggable target proteins of Salmonella Ser. Typhi biofilm and antibiofilm enzyme to prevent Salmonella Ser. Typhi biofilm-mediated infection. Enzymatic therapy has demonstrated effective therapeutic results against bacterial infections due to its specificity and high binding capacity to the target. Therefore, this study focused on the computational interaction between the cellulase enzyme and Salmonella Ser. Typhi biofilm targets proteins with help of the various computational experiments such as ADMET (absorption, distribution, metabolism, excretion, and toxicity), protein-protein interactions, MMGBSA, etc. Further, in vitro validations of the typhoidal biofilm and cellulose presence in Salmonella Ser. Typhi biofilm was conducted using Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy, and Raman analysis. Additionally, a minimum biofilm inhibitory concentration assay for cellulase was conducted and find out the optimized cellulase concentration which showed its inhibitory effect on the Salmonella Ser. Typhi. The cellulase antibiofilm effect was analyzed with the help of SEM analysis. Further, the cellulose content in Salmonella Ser. Typhi was quantified before and after treatment of cellulase enzyme. As a result, 58.82 % cellulose content was decreased due to cellulase treatment in Salmonella Ser. Typhi. From the seven selected typhoidal biofilm regulatory proteins of Salmonella Ser. Typhi, we identified only five potential druggable targets: BcsA, CsgE, OmpR, CsgF, and CsgD. The BcsA protein is responsible for cellulose production in Salmonella Ser. Typhi biofilm. Consequently, cellulose worked as a fascinating drug target in Salmonella Ser. Typhi biofilm. Therefore, we used cellulase as a potential antibiofilm enzyme for target-based disruption of biofilm. The cellulase showed a high binding affinity with all five identified target proteins [BcsA(-205.62 kcal/mol) > CsgE(-108.20 kcal/mol) > OmpR(-107.58 kcal/mol) > CsgF(-73.74 kcal/mol) > CsgD(-66.61 kcal/mol)] in the protein-protein interaction analysis. Our computational analysis suggests that the cellulase enzyme may be used as a potential antibiofilm enzyme against Salmonella Ser. Typhi biofilm.

Effect of silver nanoparticles and REP-PCR typing of Staphylococcus aureus isolated from various sources

This is the primary study at Matrouh Governorate to unveil antibiotic resistance, biofilm formation, silver nanoparticles (Ag-NPs) effect using electron microscopy, and REP-PCR analysis of Staphylococcus aureus strains isolated from COVID-19 patients, contaminated food, and Morel’s diseased sheep and goats. A total of 15 S. aureus strains were isolated; five from each of the COVID-19 patients, Morel's diseased sheep and goats, and contaminated food. All strains were considered multidrug-resistant (MDR). All strains showed the presence of biofilm. Morphological changes in the cell surface of the bacterium were evidenced, and penetration with the rupture of some bacterial cells. Based on REP-PCR analysis, 4 clusters (C1-C4) with dissimilarity between clusters C1 and C2 8% and between C3 and C4 15%. Cluster I included 3 strains from contaminated food with a similarity of 97%, and Cluster II included 2 strains from contaminated food and 2 from COVID-19-infected patients with a similarity of 96% (confirming the zoonotic nature of this pathogen). Cluster III contained 4 strains isolated from Morel's diseased sheep & goats with a similarity ratio of 99% in comparison the 4th cluster contained 3 strains isolated from COVID-patients and one from Morel's diseased sheep & goats with a similarity ratio of 92%.

Enhanced inactivation of Aspergillus niger biofilms by the combination of UV-LEDs with chlorine-based disinfectants

The presence of pathogenic fungal biofilms in drinking water distribution systems poses significant challenges in maintaining the safety of drinking water. This research delved into the formation of Aspergillus niger (A. niger) biofilms and evaluated their susceptibility to inactivation using combinations of ultraviolet light emitting diodes (UV-LEDs) with chlorine-based disinfectants, including UV-LEDs/chlorine (Cl2), UV-LEDs/chlorine dioxide (ClO2), and UV-LEDs/chloramine (NH2Cl) at 265 nm, 280 nm and 265/280 nm. Results indicated that A. niger biofilms reached initial maturity within 24 h, with matured three-dimensional filamentous structures and conidiospores by 96 h. UV-LEDs combined with chlorine-based disinfectants enhanced A. niger biofilm inactivation compared to UV-LEDs alone and low-pressure UV combined with chlorine-based disinfectants. At an UV fluence of 400 mJ/cm2, log reductions of UV265, UV280, and UV265/280 combined with chlorine-based disinfectants were 2.95-fold, 3.20-fold, and 2.38-fold higher than that of UV265, UV280, and UV265/280, respectively. During the inactivation, A. niger biofilm cells experienced increased membrane permeability and intracellular reactive oxygen species levels, resulting in cellular apoptosis. Extracellular polymeric substances contributed to the higher resistance of biofilms. Regarding electrical energy consumption, the order was: UV-LEDs/ClO2 > UV-LEDs/NH2Cl > UV-LEDs/Cl2. These findings provide insights into the effective utilization of UV-LEDs for fungal biofilm disinfection.

Nanoscale fluconazole-constructed metal-organic frameworks with smart drug release for eradication of Candida biofilms in vulvovaginitis infection

Fungal infections associated with oral, gynecological, and skin ailments pose significant clinical challenges. The presence of biofilms often hampers the efficacy of conventional antifungal drugs owing to the complex microenvironment they create. In this study, the widely used antifungal medication fluconazole is utilized as a foundational component to be incorporated into zinc 2-methylimidazolate frameworks, resulting in the synthesis of nanoscale fluconazole-constructed metal-organic frameworks (F-ZIF). The F-ZIF is constructed through coordination interactions between zinc and fluconazole, retaining the structure and pH-responsiveness of the zinc 2-methylimidazolate framework. The pH-responsiveness F-ZIF makes sure the fluconazole can be released in acidic biofilm, which prevents the undesired release in healthy tissue, resulting in good biocompatibility both in vitro and in vivo. The in vitro studies demonstrated that F-ZIF exhibits enhanced efficacy in eradicating fungal pathogens in their biofilm growth state compared with the free fluconazole. Furthermore, in vivo experiments reveal the better effectiveness of F-ZIF in treating Candida albicans-induced vulvovaginal candidiasis, and less infection-related inflammation was observed. Hence, the one-port synthetic F-ZIF presents a promising solution for addressing fungal biofilm-related infections.

Phenotypic and genotypic determination of resistance to common disinfectants among strains of Acinetobacter baumannii producing and non-producing biofilm isolated from Iran

BackgroundNosocomial infections are a global problem in hospitals all around the world. It is considered a major health problem, especially in developing countries. The increase in the patient’s stay in hospitals has increased the mortality rate, and consequently, the costs drastically increase. The main purpose of using disinfectants in the hospital environment is to reduce the risk of nosocomial infections. Ethylene diamine tetra acetic acid (EDTA) causes lysis and increases susceptibility to antimicrobial agents in the planktonic form of bacteria. This substance affects the permeability of the outer membrane of bacteria. It also prevents the formation of biofilms by bacteria.Materials and methodsIn the current study, 120 isolates of Acinetobacter baumannii (A. baumannii) were confirmed by phenotypic and genotypic methods. Antibiogram was performed and then the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of isolates against 5% sodium hypochlorite, ethanol %70, sayasept-HP 2%, chlorhexidine 2%, dettol 4/8% were evaluated. In addition, the disinfectant effect was re-evaluated with the mixture of EDTA solution. All isolates were examined for biofilm presence by crystal violet staining method in triplicates and repeated three times for each strain. Also for all isolates detection of efflux pump genes (Qac-E, qacE-Δ1, SUG-E) by PCR technique was done.ResultsAntibiogram results of A. baumannii showed that 6.7% were Multi-drug-resistant (MDR), and 89.2% were Extensively drug-resistant (XDR) isolates. The highest effect of disinfectants was related to 5% sodium hypochlorite, and the least effect was 70% ethanol. EDTA increases the efficacy of selected disinfectants significantly. The highest prevalence of the efflux pump genes was related to SUG-E (95%) and Qac-E (91.7%), and, the qacE-Δ1 gene with 12.5%. The biofilm production rate was 91.3% among all isolates.ConclusionThe best and safest way to disinfect hospital floors and surfaces is to choose the right disinfectants, and learn how to use them properly. In this study, a mixture of disinfectants and EDTA had a significant effect on bactericidal activity. it was found that improper use of disinfectants, especially the use of sub-inhibitory dilutions, increases the resistance of bacteria to disinfectants.

The effect of epigallocatechin gallate on Streptococcus Gordonii biofilm formation

Background: Dental caries, as a primary disease in dentistry, is strongly influenced by the presence of biofilms. One of the Gram-positive bacteria that acts as an initiator in the biofilm formation process is Streptococcus gordonii. As the primary catechin in green tea, epigallocatechin gallate (EGCG) is easily found in our daily lives, and it has a broad spectrum of antimicrobial effects. Several studies have revealed that EGCG inhibited the growth of Gram-positive bacteria, including inhibiting biofilm formation by damaging the bacterial cell wall and reducing glucosyltransferase activity. However, there is still limited information that explains the effect of EGCG on S. gordonii bacterial biofilms. Purpose: This study aims to analyze the effect of EGCG in inhibiting the formation of S. gordonii bacterial biofilms. Methods: This study was an in-vitro experimental laboratory study, with samples divided into five groups, namely, the group containing BHIB-bacteria, the BHIB-bacteria-5% sucrose groups, and the treatment groups containing BHIB-bacteria-5% sucrose-EGCG with concentrations of 12.5%, 6.25%, and 3.125%, respectively, incubated for 24 hours. The data was analyzed using the Kruskal–Wallis test. Results: There was a significant difference in the formation of biofilms in S. gordonii bacteria with the addition of 5% sucrose in BHIB compared with the group of S. gordonii bacteria in BHIB. The highest biofilm formation in the group containing bacteria-BHIB-5% sucrose, while the lowest biofilm formation occurred in the treatment group containing bacteria-BHIB-5% sucrose-12.5% EGCG with significant difference between the group. Conclusion: The addition of EGCG 12.5% inhibits the formation of S. gordonii biofilms.

Critical areas for <i>Brettanomyces bruxellensis</i> contamination and biofilm formation in the cellar: on the origin of wine spoilage

The cellar environment harbours a consortium of microorganisms on the material surfaces and in the air. Among these microorganisms, the spoilage yeast Brettanomyces bruxellensis can colonise surfaces due to its specific bioadhesive properties. In this study, air and surface samples were collected in several wineries during the winter period. B. bruxellensis was detected in the cellar environment either in the air or on the surfaces of various materials, including in tartaric acid precipitates. Difficult-to-clean tank equipment (taps, wall angles, valves) were identified as critical areas where B. bruxellensis was frequently detected. To confirm that surfaces contaminated by B. bruxellensis could be involved in wine contamination, yeast growth and volatile phenol production were monitored in wine in contact with stainless steel harbouring biofilms. The presence of bioadherent cells and biofilms in contact with the wine resulted in significant cell release into the wine, leading to population growth and the production of volatile phenols at concentrations above the olfactory detection threshold. This study demonstrates the possibility of wine spoilage by resident and adherent populations of B. bruxellensis and confirms the need to pay special attention to the hygiene of hard-to-reach areas such as valves.

Dental caries lesions and impact on quality of life in adolescents living in urban and rural areas. A case study.

The concept of quality of life (QoL) developed from early studies on subjective wellbeing and satisfaction with life, interpreted as resulting from living conditions, and recognized by means of objective indicators. Indicators have been developed and validated to measure the relationship between quality of life and health Aim: To determine, during an Educational Social Practice, the association between presence of dental caries lesions and its impact on quality of life of adolescents living in rural and urban areas in Argentina. Materials and Method: This was an observational cross-sectional study in (a) a rural area (Tres Isletas; Chaco Province/Schools No. 601 and 477) and (b) an urban area (Villa Soldati; Buenos Aires City/Nuestra Sra. Fátima School). The sample included 40 students from the urban area (UG) and 30 from the rural area (RG). A calibrated researcher (Kappa 0.80) collected the survey data and performed the clinical examinations. The following were recorded: (a) sociodemographic distribution in terms of age and gender; (b) presence of dental biofilm according to Silness and Löe; caries lesions according to ICDAS II /INTCy criteria, and (d) DMFT, total and per component. Quality of life was assessed using the CPQ 11-14r. Statistical processing included calculation of frequency distribution of the variables (X± DS), and chi-square and Mann-Whitney tests to calculate association and comparisons between groups. Results: The sample included 47 girls (67.1%) and 23 boys (32.9%). Distribution according to sex and age did not differ significantly between sites (UG:12.9 years ± 0.5 and RG:11.8 years ±1.1). No significant difference was found between sites for a) plaque biofilm (p=0.759); b) DMFT, total value and per component, or c) individual and grouped ICDAS scores. Percentage analysis of the CPQr 1-14 scores showed significant differences between groups for questionnaire total scores (26.9% ± 2.2 in UG and 4.1% ± 0.8 in RG) and for the different domains. Conclusion: Perceived impact on quality of life caused by dental caries lesions was significantly higher in urban than the rural group, although neither the dental caries process nor the amount of biofilm differed significantly between groups.