Search

This publication highlights the latest advancements in the field of energy and nutrient recovery from organics rich municipal and industrial waste and wastewater. Energy and carbon rich waste streams are multifaceted, including municipal solid waste, industrial waste, agricultural by-products and residues, beached or residual seaweed biomass from post-harvest processing, and food waste and are valuable resources to overcome current limitations with sustainable feedstock supply chains for biorefining approaches. The emphasis will be on the most recent scientific progress in the area, including the development of new and innovative technologies, such as microbial processes and the role of biofilms for the degradation of organic pollutants in wastewater, as well as the production of biofuels and value-added products from organic waste and wastewater streams. The carboxylate platform, which employs microbiomes to produce mixed carboxylic acids through methane-arrested anaerobic digestion, is the focus as a new conversion technology. Nutrient recycling from conventional waste streams such as wastewater and digestate, and the energetic valorization of such streams will also be discussed. The selected technologies significantly contribute to advanced waste and wastewater treatment and support the recovery and utilization of carboxylic acids as the basis to produce many useful and valuable products, including food and feed preservatives, human and animal health supplements, solvents, plasticizers, lubricants, and even biofuels such as sustainable aviation fuel.

Purpose: This study aimed to investigate the inhibitory effect of a PRG Barrier Coat on biofilm formation and structure by Streptococcus mutans and propose an effective method for preventing dental caries. Materials and Methods: Streptococcus mutans MT8148 biofilms were obtained from hydroxyapatite disks with and without a PRG Barrier Coat. Scanning electron microscopy (SEM) was used to observe the 12- and 24-h-cultured biofilms, while reverse-transcription polymerase chain reaction (qRT-PCR) was used to quantify caries-related genes. Biofilm adhesion assessments were performed on glass. Statistical analysis was performed using a two-sample t-test. Results: A statistically significant difference in Streptococcus mutans biofilm adhesion rate was observed between the control and PRG Barrier Coat-coated samples (p < 0.01). However, there was no statistically significant difference in total bacterial count or biofilm volume (p > 0.05). SEM revealed that the PRG Barrier Coat inhibited biofilm formation by Streptococcus mutans. Real-time RT-PCR revealed that the material restricted the expression of genes associated with caries-related biofilm formation. However, the suppression of gtfD and dexB differed from that of other genes. Conclusion: PRG Barrier Coat suppressed biofilm formation by Streptococcus mutans by inhibiting the expression of insoluble glucan synthase, which is associated with primary biofilm formation. The material also affected gene expression and altered the biofilm structure. Tooth surface-coating materials, such as PRG Barrier Coat, may improve caries prevention in dental practice. [ABSTRACT FROM AUTHOR]

Frankincense is produced by Boswellia trees, 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 antimicrobial 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, the effects on Fusobacterium nucleatum growth and biofilm formation were not significant. Using quantification of colony-forming units 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 potential for preventing and/or treating periodontal diseases. Future studies will identify the molecular components of B. serrata extracts responsible for the beneficial effects.

The growing concerns regarding foodborne illnesses related to fresh produce accentuate the necessity for innovative material solutions, particularly on surfaces that come into close contact with foods. This study introduces a sustainable, efficient, and removable antimicrobial and antifouling coating ideally suited for hydrophobic food-contact surfaces such as low-density polyethylene (LDPE). Developed through a crosslinking reaction involving tannic acid, gelatin, and soy protein hydrolysate, these coatings exhibit proper stability in aqueous washing solutions and effectively combat bacterial contamination and prevent biofilm formation. The unique surface architecture promotes the formation of halamine structures, enhancing antimicrobial efficacy with a rapid contact killing effect and reducing microbial contamination by up to 5 log10 cfu·cm-2 against both Escherichia coli (Gram-negative) and Listeria innocua (Gram-positive). Notably, the coatings are designed for at least five recharging cycles under mild conditions (pH6, 20 ppm free active chlorine) and can be easily removed with hot water or steam to refresh the depositions. This removal process not only conveniently aligns with existing sanitation protocols in the fresh produce industry but also facilitates the complete eradication of potential developed biofilms, outperforming uncoated LDPE coupons. Overall, these coatings represent sustainable, cost-effective, and practical advancements in food safety and are promising candidates for widespread adoption in food processing environments.

The predominant use of intravenous catheters as primary access type in the pediatric hemodialysis population is associated with an increased risk of catheter related blood stream infections. While strict adherence to catheter placement and long-term care guidelines have helped to decrease the incidence of these infections, blood stream infections remain an infection burden in pediatric patients with long term hemodialysis catheters. The formation of biofilms on the surfaces of these catheters has been shown to be a source of microbes causing blood stream infections. One of the strategies for preventing bacterial colonization, inhibiting microbial multiplication, and suppressing the seeding of these microbes from biofilms upon maturation, has been the use of antibiotic-based lock solutions in-between dialysis treatments. Although clinical guidelines for the use of antibiotic lock solutions are yet to be developed, available evidence suggests a beneficial role of antibiotic lock solutions in the management of catheter related blood stream infections. Additionally, a clear understanding of how biofilms are formed and their role in the pathogenesis of catheter related bloodstream infection will facilitate the development of solutions that can prevent biofilm formation and inhibit their multiplication, maturation and seeding into the bloodstream.

Aquaculture is one of the most significant food sources from the prehistoric period. As aquaculture intensifies globally, the prevalence and outbreaks of various pathogenic microorganisms cause fish disease and heavy mortality, leading to a drastic reduction in yield and substantial economic loss. With the modernization of the aquaculture system, a new challenge regarding biofilms or bacterial microenvironments arises worldwide, which facilitates pathogenic microorganisms to survive under unfavorable environmental conditions and withstand various treatments, especially antibiotics and other chemical disinfectants. However, we focus on the mechanistic association between those microbes which mainly form biofilm and probiotics in one of the major food production systems, aquaculture. In recent years, probiotics and their derivatives have attracted much attention in the fisheries sector to combat the survival strategy of pathogenic bacteria. Apart from this, Bibliometric analysis provides a comprehensive overview of the published literature, highlighting key research themes, emerging topics, and areas that require further investigation. This information is valuable for researchers, policymakers, and stakeholders in determining research priorities and allocating resources effectively. [ABSTRACT FROM AUTHOR]

Antibiotic resistance genes (ARGs) are emerging pollutants that are widely present in the environment, and are affected by microplastics (MPs). The coexistence of MPs and ARGs enhances their abundance and transmission ability, thereby increasing their environmental hazard. This study summarized the effects of MPs on the abundance and transmission of ARGs. First, the effects of MPs on ARGs in aquatic, terrestrial, atmospheric, and animal intestinal environments were analyzed. Furthermore, factors that affect the enrichment and transfer ability of MPs, including MPs properties, human activities, environmental factors, and other pollutants, were discussed. Previous studies mainly focused on the abundance changes, propagation and diffusion of ARGs on MPs, however, the possible mechanism of these changes on ARGs caused by MPs has not been fully studied, which also leads to many explanations that are not appropriate. Therefore, in the fourth section, the detailed mechanism of MPs on abundance and transfer of ARGs is systematically discussed. As the core innovation in this article, it fills the gap that has been to be supplemented in recent years. Finally, the research challenges and prospects of the effects of MPs on the abundance and spread of ARGs are proposed in the hope that this review will be helpful to better understand the environmental risks and mechanisms of MPs on ARGs. [ABSTRACT FROM AUTHOR]

In spite of multipurpose technologies offering broad-spectrum prevention for sexually transmitted infections (STIs) and contraception, the STIs incidences rise worldwide. The situation is even more alarming considering continuous rise in antimicrobial resistance (AMR) that limits therapy options. In this review we address the specific challenges of efficiently treating vaginal infections locally, at the infection site, by understanding the underlying barriers to efficient treatment such as vaginal biofilms. Knowledge on vaginal biofilms remains, up to now, rather scarce and requires more attention. We therefore propose a 'back to basics' insight that seeks to probe the complexity and role of the vaginal microbiota, its relationship with vaginal biofilms and implications to future therapeutic modalities utilizing advanced nano delivery systems. Our key objective is to highlight the interplay between biofilm, (nano)formulation and therapy outcome rather than provide an overview of all nanoformulations that were challenged against biofilms. We focused on the anatomy of the female reproductive organ and its physiological changes from birth, the unique vaginal microenvironment in premenopausal and postmenopausal women, vaginal biofilm infections and current nanomedicine-based approaches to treat infections in the vaginal site. Finally, we offer our perspectives on the current challenges associated with vaginal delivery and key considerations that can aid in the design and development of safer and potent products against persisting vaginal infections. [Display omitted] [ABSTRACT FROM AUTHOR]

ABSTRACT The process of biofilm formation during table olive fermentation is crucial to turning this fermented vegetable into a probiotic food. Some phenolic compounds have been described as important quorum‐sensing molecules during biofilm development. The present in vitro study examined the effects of three phenolic compounds widely found in table olive fermentations (Oleuropein 0–3000 ppm, Hydroxytyrosol 0–3000 ppm, and Tyrosol 0–300 ppm) on the development of single biofilm by diverse microorganisms isolated from table olives (Lactiplantibacillus pentosus 13B4, Lp119, and LPG1; Lactiplantibacillus plantarum Lp15 and LAB23; and yeasts Wickerhamomyces anomalus Y12, Candida boidinii Y13, and Saccharomyces cerevisiae Y18). Biofilm formation was quantified in vitro by crystal violet staining in microtiter plates after incubation at 30°C for 96 h. A clear tendency to decrease the biofilm production was observed for the L. plantarum strains when any of the three phenolic compounds were added to the medium, which was statistically significant (p ≤ 0.05) for certain concentrations and phenols. In the case of yeasts, no statistical influence on biofilm formation was noticed when the phenolic compounds were dosed to the culture medium. Finally, the effects of the phenolic compounds on the L. pentosus strains were dependent on the strain assayed. Thereby, addition of phenolic compounds on 13B4 or Lp119 strains did not have statistical influence on biofilm production. On the contrary, the probiotic LPG1 strain noticed a statistical increase in biofilm production when a low concentration of tyrosol (50 ppm) was added to the medium. Results obtained in this work could be useful to control the biofilm formation process on olive epidermis during table olive fermentation to include beneficial microorganisms. [ABSTRACT FROM AUTHOR]

The diversity and delicate balance of the oral microbiome contribute to oral health, with its disruption leading to oral and systemic diseases. Toothpaste includes elements like traditional additives such as sodium lauryl sulfate (SLS) as well as novel postbiotics derived from probiotics, which are commonly employed for maintaining oral hygiene and a healthy oral cavity. However, the response of the oral microbiota to these treatments remains poorly understood. In this study, we systematically investigated the impact of SLS, and toothpaste containing postbiotics (hereafter, postbiotic toothpaste) across three systems: biofilms, animal models, and clinical populations. SLS was found to kill bacteria in both preformed biofilms (mature biofilms) and developing biofilms (immature biofilms), and disturbed the microbial community structure by increasing the number of pathogenic bacteria. SLS also destroyed periodontal tissue, promoted alveolar bone resorption, and enhanced the extent of inflammatory response level. The postbiotic toothpaste favored bacterial homeostasis and the normal development of the two types of biofilms in vitro, and attenuated periodontitis and gingivitis in vivo via modulation of oral microecology. Importantly, the postbiotic toothpaste mitigated the adverse effects of SLS when used in combination, both in vitro and in vivo. Overall, the findings of this study describe the impact of toothpaste components on oral microflora and stress the necessity for obtaining a comprehensive understanding of oral microbial ecology by considering multiple aspects. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the effect of honokiol combined with resveratrol on bacteria responsible for oral malodor and their biofilm. Method: This study investigated drug's MIC, FICI and dynamic bactericidal susceptibility activities against Pg and Fn. The effects of drugs on biofilm metabolic activity, biofilm total amount, and biofilm microstructure were determined by CCK-8 experiment, semi-quantitative adhesion experiment and SEM, respectively. The effects of drugs on biofilm genes, extracellular polysaccharides, proteins and DNA content were determined by qRT-PCR, phenol-sulfuric acid method, BCA method and Nano Drop one C, respectively. Results: The combination had synergistic antibacterial effect on Pg and Fn. 1/2×MIC and 1×MIC combination inhibit the whole process of Pg and Fn growth. The results showed that the combination effectively reduce biofilm metabolic activity and total amount, and destroy biofilm microstructure. The results showed that the combination downregulate the gene expression both Pg and Fn, reduce extracellular polysaccharides and DNA of Pg, and reduce extracellular proteins and DNA of Fn. Conclusion: This study showed that the combination had a synergistic antibacterial effect on Pg and Fn, reduced the biofilm extracellular matrix, inhibited biofilm formation, and downregulated the expression of genes related to biofilm formation. [ABSTRACT FROM AUTHOR]

Background: The oral microbiome is a complex and dynamic assemblage of microorganisms that colonize different sites of the oral cavity maintaining both oral and systemic health. Therefore, when its composition is altered, oral diseases occur. Among oral inflammatory pathologies, periodontal diseases affect the tissues surrounding the teeth, representing the main cause of tooth loss and one of the most important threats to the oral health. Lifestyle and eating habits influence the composition of the human oral microbiota and the development and progression of oral diseases. In this context, the Mediterranean Diet (MD) model, comprising both healthy dietary choices and lifestyle, is linked to the prevention of several metabolic and chronic-degenerative pathological processes, including oral diseases. Indeed, the MD is a plant-based diet, enriched of anti-inflammatory and antioxidant nutrients, which may induce beneficial effects against dental caries and periodontal diseases. Aim: This review summarizes the role of the oral microbiome in the development of the oral diseases and the potential of MD in modulating the oral microbiome leading to implications for oral health. Conclusions: The data collected highlight the need to promote the MD pattern along with the correct hygiene habits to prevent the development of oral diseases. 3 key messages: The oral microbiome is a complex and dynamic assemblage of microorganisms that colonize different sites of the oral cavity maintaining both oral and systemic health. The Mediterranean Diet (MD) model, comprising both healthy dietary choices and lifestyle, is linked to the prevention of several metabolic and chronic degenerative pathological processes, including oral diseases. The MD may represent a potential player in the link between oral microbiome and oral diseases. [ABSTRACT FROM AUTHOR]

Aim: To determine the antimicrobial activity of the bacteriocin-producing probiotic strains Streptococcus salivarius K12 and Streptococcus salivarius M18 alone or in combination against caries-associated Streptococcus mutans. Methods: Antimicrobial activity of S. salivarius K12 and/or S. salivarius M18 against S. mutans ATCC 25175 growth and biofilm formation on hydroxyapatite (HA) discs was determined in a flow chamber model by recording the colony forming units (CFU/ml) after 48 h of co-cultivation. The biofilm was analyzed by scanning electron microscopy (SEM) and by confocal laser scanning microscopy (CLSM). Additionally, the simultaneous antagonism assay was used to assess the inhibitory effect of S. salivarius K12 and/or S. salivarius M18 against S. mutans ATCC 25175 and 21 clinical isolates of S. mutans. Results: Co-cultivation of S. mutans and S. salivarius K12 and/or S. salivarius M18 led to the inhibition of S. mutans viability, thereby, preventing its biofilm formation on HA discs. Furthermore, S. salivarius K12 and S. salivarius M18 exhibited antimicrobial activity against most clinical isolates of S. mutans. Conclusion: The in vitro flow chamber system used in this study allows the simulation of time-dependent administration of S. salivarius probiotic strains, either alone or in combination, to investigate the prevention of S. mutans biofilm formation in a standardized model. [ABSTRACT FROM AUTHOR]

Aims: The current study aimed to explore the adjuvant therapeutic effect of N-acyl homoserine lactones (AHLs)-lactonase est816 on Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) biological behaviors and periodontitis progression. Methods: The inhibitory properties of est816 were detected by live/dead bacterial staining, scanning electron microscope (SEM), crystal-violet staining and reverse-transcription quantitative PCR (RT-qPCR). Biocompatibility of est816 on human gingival fibroblasts (HGFs) and human gingival epithelial cells (HGEs) was evaluated by CCK8 and ELISA. The ligature-induced periodontitis model was established in rats. Micro computed tomography and immunohistochemical and histological staining served to evaluate the effect of est816 on the prevention of periodontitis in vivo. Results: est816 significantly attenuated biofilm formation, reduced the mRNA expression of cytolethal distending toxin, leukotoxin and poly-N-acetyl glucosamine (PNAG) and downregulated expressions of interleukin-6 and tumor necrosis factor-α with low cell toxicity. In vivo investigations revealed est816 decreased alveolar bone resorption, suppressed matrix metalloproteinase-9 expression and increased osteoprotegerin expression. Conclusion: est816 inhibited A. actinomycetemcomitans biofilm formation and virulence release, resulting in anti-inflammation and soothing of periodontitis in rats, indicating that est816 could be investigated in further research on periodontal diseases. [ABSTRACT FROM AUTHOR]

Objectives: Microbial contamination of various accessory parts of the dental chair units (DCUs) is an essential source of cross infection, while the accessories of the crucial suction function are usually overlooked. In this study, we aim to find an effective disinfectant and a cost-effective method to remove bacterioplankton and bacterial biofilm deposited in the negative pressure suction pipelines to control cross infection during dental treatment. Methods: Double-chain quaternary ammonium salt disinfectant (Orotol Plus®), 3% hydrogen peroxide solution plus multi-enzyme cleaning agent and chlorine disinfectant are used to clean and disinfect the negative pressure pipelines of DCUs. Microbiological examinations, air condition detection, corrosion tests and gene sequencing are performed. Results: Little bacteria grow in the pipelines disinfected with double-chain quaternary ammonium salt disinfectants, destruction of biofilms in these pipelines appears, and multi-resistant bacteria cannot be detected. Minimal damage to metal sheets and fittings is caused by double-chain quaternary ammonium salt disinfectants. Conclusion: Double-chain quaternary ammonium salt disinfectant has excellent bactericidal ability and anti-biofilm effect, and it is less corrosive to the fittings of the pipelines. Thus, the double-chain quaternary ammonium salt disinfectant is a potential novel disinfectant for negative pressure suction pipelines of DCUs to control cross infection during dental treatment. Clinical significance: It is essential to add all these data to our dental practice to control cross infection with a broader landscape. [ABSTRACT FROM AUTHOR]

Background: The biofilm formation in Dental Unit Waterlines (DUWLs) could become an important cause of infection during dental care, which could put immunocompromised individuals at risk of cross-infection. The aim of this study was to characterize the microbial communities of biofilms among DUWLs using high-throughput sequencing technology. Methods: Twenty-nine biofilm samples were obtained from 24 dental chair units at 5 hospitals and 2 dental clinics. The genomic DNA of the samples was extracted, then 16S rDNA and ITS2 gene were amplified and sequenced. Alpha-diversity and Beta-diversity were calculated with QIIME2 and the Kruskal – Wallis H-test was adopted for statistical analysis. Results: Microbial communities with a high diversity of bacteria (377 genera) and fungi (83 genera) were detected in the biofilm samples. The dominant phylum of bacteria was Proteobacteria (93.27%) and that of fungi was Basidiomycota (68.15%). Potential human pathogens were detected including 7 genera of bacteria (Pseudomonas, Stenotrophomonas, Hafnia-Obesumbacterium, Burkholderia-Caballeronia-Paraburkholderia, Ralstonia, Enterobacter, Klebsiella) and 6 genera of fungi (Malassezia, Candida, Alternaria, Cryptococcus, Rhodotorula, Rhinocladiella). Conclusions: This multicenter assessment revealed the infectious risk during dental care. It emphasized the importance of biofilm control due to biofilm accumulation and multiple kinds of opportunistic pathogens in DUWLs. [ABSTRACT FROM AUTHOR]

Background: Three-dimensional (3D) tissue models bridge the gap between conventional two-dimensional cell cultures and animal models. The aim of this study was to develop an organotypic 3D gingival (OTG) model to provide a tool to investigate bacterial and viral pathogens in periodontitis. Methods: The OTG model composed of gingival fibroblasts (GFs) and telomerase-immortalized gingival keratinocytes (TIGKs) was constructed and applied to study infections by Porphyromonas gingivalis and herpes simplex virus 1 (HSV-1). Immunohistochemical staining, confocal microscopy, qPCR, titration techniques, and colony-forming unit counts were applied to interrogate epithelial markers expression, monitor P. gingivalis and HSV-1 presence, and evaluate the immune response along with the efficiency of antimicrobial drugs. Results: The OTG model resembled the morphology of the human gingiva. During infection, both pathogens penetrated deep into the tissue and persisted for a few days with P. gingivalis also forming a biofilm on the cell surface. The infection triggered the expression of inflammatory mediators in cells and both pathogens were efficiently eliminated by specific antimicrobials. Conclusions: Presented OTG model constitutes a simple and convenient tool to study the interaction between bacterial and viral pathogens within the gingival tissue, including penetration, persistence and biofilm formation. It is also suitable to examine the efficiency of antimicrobial drugs. [ABSTRACT FROM AUTHOR]

Malassezia furfur is a yeast known as the etiological agent of seborrheic dermatitis. We evaluated the action of five different antimicrobials (amphotericin B, chloramphenicol, ketoconazole, fluconazole, and nystatin) on inhibiting biofilm formation and removing biofilm already formed by M. furfur. The assays were carried out using the microdilution method, and scanning electron microscopy images were used to analyze the biofilm structure. According to the results obtained, the percentage of inhibition was higher for chloramphenicol, followed by ketoconazole, nystatin, and amphotericin B. Regarding the eradication of the biofilm formed, the highest percentage was chloramphenicol, followed by ketoconazole and nystatin. Amphotericin B did not affect biofilm eradication, whereas fluconazole did not cause significant changes inhibiting or removing M. furfur biofilm. Therefore, except for fluconazole, all evaluated antimicrobials had inhibiting effects on the biofilm of M. furfur, either in its formation and/or eradication. Although the results achieved with chloramphenicol have been highlighted, further in vitro and in vivo studies are still needed in order to include this antimicrobial in the therapy of seborrheic dermatitis due to its toxicity, especially to the bone marrow. [ABSTRACT FROM AUTHOR]

Azithromycin (AZM) is efficient for treatment of chronic Pseudomonas aeruginosa biofilm lung infections, despite of resistance in conventional susceptibility testing. It has been shown that planktonic P. aeruginosa are more susceptible to AZM when tested in RPMI 1640 medium. The aim of the study was to test the susceptibility to AZM of P. aeruginosa biofilms in LB vs RPMI 1640 media. We investigated the effect of AZM on planktonic and biofilms of (WT) P. aeruginosa (PAO1), the hypermutable (ΔmutS) and the antibiotic‐resistant phenotype(ΔnfxB) mutants. The effect of AZM on young and mature biofilms was investigated in the modified Calgary Biofilm Device by estimation of the minimal biofilm inhibitory concentration (MBIC). The AZM MBIC90 in LB/RPMI1640 on young biofilms treated for 24 h was 16/4 μg/mL for PAO1, 32/8 μg/mL for ΔmutS, and 256/16 μg/mL for ΔnfxB, while in mature biofilms was 256/2 μg/mL for PAO1 and ΔmutS and 16/1 μg/mL for ΔnfxB. The effect of AZM was improved when the treatment was prolonged to 72 h, supporting the intracellular accumulation of AZM. An increased susceptibility of P. aeruginosa biofilms to AZM was observed in RPMI 1640 than in LB medium. Our results might improve susceptibility testing and dosing of AZM for treatment of biofilm infections. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus (S. aureus) is one of the important pathogenic bacteria found in urban sewage that shows resistance to different classes of antibiotics. Therefore, the aim of the current study is to assess the antibacterial and anti-biofilm effects of Ciprofloxacin-loaded niosomes (Nio-Cip) formulation on S. aureus isolated from urban wastewater samples. The Nio-Cip was synthesized using the thin-layer hydration method and was formulated based on two variables: lipid content and the ratio of surfactant to cholesterol. The F5 formulation was selected as the optimal formulation among other preparations due to its small size (185 nm) and high drug entrapment efficiency (78.65%). The rate of drug release over 72 h from niosomal formulation was 70% in a biphasic manner. The microbial study showed that out of 50 isolates from urban wastewater, 15 MRSA strains had icaA and icaD genes. Also, the obtained MIC of Nio-Cip was dramatically smaller than that of Cip alone (1–16 μM compared to 8–32 μM). The ability to form biofilm in these strains was greatly reduced after treatment with Cip and Nio-Cip. Based on our abservation, Nio-Cip had higher antibiofilm effects against MRSA than Cip (more than twofold), These results were confirmed with greater down-regulation of icaA and icaD gene expression in Nio-Cip _treated isolates compared to Cip-treated bacteria using the real-time PCR method. Nevertheless, more studies are needed to investigate the anti-biofilm mechanism of Nio-Cip to recognize this method as a novel strategy for the treatment of MDR strains of S. aureus. [ABSTRACT FROM AUTHOR]

We analyze travelling wave (TW) solutions for nonlinear systems consisting of an ODE coupled to a degenerate PDE with a diffusion coefficient that vanishes as the solution tends to zero and blows up as it approaches its maximum value. Stable TW solutions for such systems have previously been observed numerically as well as in biological experiments on the growth of cellulolytic biofilms. In this work, we provide an analytical justification for these observations and prove existence and stability results for TW solutions of such models. Using the TW ansatz and a first integral, the system is reduced to an autonomous dynamical system with two unknowns. Analysing the system in the corresponding phase–plane, the existence of a unique TW is shown, which possesses a sharp front and a diffusive tail, and is moving with a constant speed. The linear stability of the TW in two space dimensions is proven under suitable assumptions on the initial data. Finally, numerical simulations are presented that affirm the theoretical predictions on the existence, stability, and parametric dependence of the travelling waves. [ABSTRACT FROM AUTHOR]

Dense communities of bacteria, also known as biofilms, are ubiquitous in all of our everyday life. They are not only always surrounding us, but are also active inside our bodies, for example in the oral cavity. While some biofilms are beneficial or even necessary for human life, others can be harmful. Therefore, it is highly important to gain an in-depth understanding of biofilms which can be achieved by in vitro or in vivo experiments. Since these experiments are often time-consuming or expensive, in silico models have proven themselves to be a viable tool in assisting the description and analysis of these complicated processes. Current biofilm growth simulations are using mainly two approaches for describing the underlying models. The volumetric approach splits the deformation tensor into a growth and an elastic part. In this approach, the mass never changes, unless some additional constraints are enforced. The density-based approach, on the other hand, uses an evolution equation to update the growing tissue by adding mass. Here, the density stays constant, and no pressure is exerted. The in silico model presented in this work combines the two approaches. Thus, it is possible to capture stresses inside of the biofilm while adding mass. Since this approach is directly derived from Hamilton's principle, it fulfills the first and second law of thermodynamics automatically, which other models need to be checked for separately. In this work, we show the derivation of the model as well as some selected numerical experiments. The numerical experiments show a good phenomenological agreement with what is to be expected from a growing biofilm. The numerical behavior is stable, and we are thus capable of solving complicated boundary value problems. In addition, the model is very reactive to different input parameters, thereby different behavior of various biofilms can be captured without modifying the model. [ABSTRACT FROM AUTHOR]

Purpose: Periprosthetic joint infection is a complication of total joint arthroplasty with treatment costs over $1.6 billion dollars per year in the US with high failure rates. Therefore, generation of coatings that can prevent infection is paramount. Diamond-like carbon (DLC) is an ideal coating for implants as they are wear-resistant, corrosion-resistant, inert, and have a low friction coefficient. The purpose of this study was to test the efficacy of DLC surface treatment in prevention of biofilm on titanium discs infected with Staphylococcus aureus in vitro. Methods: Titanium alloy discs (n = 4 non-coated and n = 4 DLC-coated) were infected with 5 × 105 colony-forming units (CFU) of S. aureus for 2 weeks then analysed via crystal violet and scanning electron microscopy (SEM). Results: Crystal violet analysis yielded differences in the appearance of biofilm on implant surface where DLC-coated had a clumpier appearance but no difference in biofilm quantification. Interestingly, this clumpy appearance did lead to differences in SEM biofilm coverage where significantly less biofilm coverage was found on DLC-coated discs (81.78% vs. 54.17%, p < 0.003). Conclusion: DLC-coated titanium alloy implants may have preventative properties in S. aureus infection. Observing differences in biofilm coverage does warrant additional testing including CFU titration and biofilm kinetics with eventual use in an animal model of periprosthetic joint infection. [ABSTRACT FROM AUTHOR]

Despite some effectiveness of wastewater treatment processes, microplastics accumulate in sewage sludge and their further use may contribute to the release of plastic microplastics into the environment. There is an urgent need to reduce the amount of microplastics in sewage sludge. Plastic particles serve as solid substrates for various microorganisms, promoting the formation of microbial biofilms with different metabolic activities. The biofilm environment associated with microplastics will determine the efficiency of treatment processes, especially biological methods, and the mechanisms of organic compound conversion. A significant source of microplastics is the land application of sewage sludge from wastewater treatment plants. The detrimental impact of microplastics affects soil enzymatic activity, soil microorganisms, flora, fauna, and plant production. This review article summarizes the development of research related to microplastics and discusses the issue of microplastic introduction from sewage sludge. Given that microplastics can contain complex composite polymers and form a plastisphere, further research is needed to understand their potential environmental impact, pathogenicity, and the characteristics of biofilms in wastewater treatment systems. The article also discusses the physicochemical properties of microplastics in wastewater treatment plants and their role in biofilm formation. Then, the article explained the impact of these properties on the possibility of the formation of biofilms on their surface due to the peculiar structure of microorganisms and also characterized what factors enable the formation of specific plastisphere in wastewater treatment plants. It highlights the urgent need to understand the basic information about microplastics to assess environmental toxicity more rationally, enabling better pollution control and the development of regulatory standards to manage microplastics entering the environment. [ABSTRACT FROM AUTHOR]

Bacteriocins are gene-encoded antimicrobial peptides produced by bacteria. These peptides are heterogeneous in terms of structure, antimicrobial activities, biosynthetic clusters, and regulatory mechanisms. Bacteriocins are widespread in nature and may contribute to microbial diversity due to their capacity to target specific bacteria. Primarily studied as food preservatives and therapeutic agents, their function in natural settings is however less known. This review emphasizes the ecological significance of bacteriocins as multifunctional peptides by exploring bacteriocin distribution, mobility, and their impact on bacterial population dynamics and biofilms. [ABSTRACT FROM AUTHOR]

The present study investigates the low temperature tolerance strategies of thermophilic bacterium Anoxybacillus rupiensis TPH1, which grows optimally at 55 °C , by subjecting it to a temperature down-shift of 10 °C (45 °C) for 4 and 6 h followed by studying its growth, morphophysiological, molecular and proteomic responses. Results suggested that although TPH1 experienced increased growth inhibition, ROS production, protein oxidation and membrane disruption after 4 h of incubation at 45 °C yet maintained its DNA integrity and cellular structure through the increased expression of DNA damage repair and cell envelop synthesizing proteins and also progressively alleviated growth inhibition by 20% within two hours i.e., 6 h, by inducing the expression of antioxidative enzymes, production of unsaturated fatty acids, capsular and released exopolysaccharides and forming biofilm along with chemotaxis proteins. Conclusively, the adaptation of Anoxybacillus rupiensis TPH1 to lower temperature is mainly mediated by the synthesis of large numbers of defense proteins and exopolysaccharide rich biofilm formation. [ABSTRACT FROM AUTHOR]

Sink drains in hospitals are notorious reservoirs of bacteria, hosting both planktonic micro-organisms and biofilms within the siphon. Disinfectants based on peracetic acid are both non-corrosive and effective in eliminating biofilm and planktonic micro-organisms, presenting a potential solution for decontaminating sink drains. To examine the effectiveness of Clinell Drain Disinfectant, a peracetic-acid-based disinfectant, in the intensive care unit (ICU) of UZ Brussel. All 10 sinks in one of the ICU subunits known to be heavily contaminated were treated with Clinell Drain Disinfectant for one month. Throughout the treatment period, bacterial growth in the P-traps was systematically monitored qualitatively (using eSwab) and quantitatively (employing a sterile catheter and syringe) on various selective agar plates, processed and incubated in the WASPLab system. Matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy was used to identify all morphologically distinct colonies. At baseline, most of the sink drains were colonized by high concentrations of multidrug-resistant micro-organisms, primarily VIM-producing P. aeruginosa. The cultures taken immediately after decontamination yielded negative results, with only a very few exceptions. Nonetheless, it was observed that the biofilm in the upper section of the drain system remained unaffected, and within two days it was capable of recolonizing the liquid in the P-traps at a concentration >100,000 cfu/mL. After one month, this disinfecting protocol did not result in a lasting decontamination of the sink drains. This study demonstrated the disinfectant's efficacy in decontaminating the P-trap liquid. [ABSTRACT FROM AUTHOR]

Porphyromonas gulae is a major causative agent of periodontal disease in companion animals that possesses various virulence factors, including fimbriae, lipopolysaccharides, and proteases. P. gulae fimbriae are classified into three genotypes (A, B, and C) based on their nucleotide sequences. Type C fimbrial isolates have been reported to be more virulent than other fimA types, suggesting that different fimA types may aid in the regulation of periodontal pathogenesis. Detailed findings regarding the ability of P. gulae to form biofilms have yet to be reported. Here, we investigated the contributions of fimbrial genotypes in P. gulae biofilm formation. P. gulae and P. gingivalis biofilms were generated on plates and analyzed using confocal laser microscopy. Additionally, the biofilms formed were assessed by staining with crystal violet. Furthermore, the physical strength of P. gulae biofilms was examined by ultrasonication. Biofilms formed by P. gulae type C were denser than those formed by types A and B. Moreover, the amount of biofilm formed by type C strains was significantly greater than that formed by type A and B strains, which was similar to the biofilms formed by P. gingivalis with type II fimbriae. Additionally, the physical strength of the type C biofilm was significantly greater than that of the other strains. These results suggest that FimA variation may coordinate for biofilm formation. This is the first report on the observation and characterization of P. gulae biofilm formation. • The formation of biofilm by P. gulae occurs in fimA genotypes manner. • The biofilm amounts formed by type C strains is greater than type A and B strains. • The physical strength of type C strain biofilm is significantly greater than other type strains. [ABSTRACT FROM AUTHOR]

Arctic streams are highly sensitive to climate change and their biological communities are subjected to considerable changes. Benthic diatom communities are an important basal resource for higher trophic levels in these oligotrophic streams. However, our knowledge on how they respond to stream physicochemical characteristics in the Arctic is limited. The objective of this study was to describe diatom communities' characteristics and assess how they are related to physicochemical parameters in 15 stream reaches in Northeast Greenland. Overall, we found 36 species across the streams from which Planothidium frequentissimum was the most abundant followed by Nitzschia palea. Based on physicochemical variables, including water nitrogen concentration, dissolved organic carbon concentrations and conductivity, the sampling sites were separated into three stream types: headwater, valley and glacial and snowpack runoff streams. Trait analyses showed that the majority of the species belonged to the 'macro' cell size category, strongly correlated with higher concentration of nitrogen. Diatom diversity was negatively affected by water velocity with glacial and snowpack runoff streams to be characterized by the lower number of species. Very small variation was explained solely by the physicochemical variables indicating that the distribution of diatom communities is influenced significantly by catchment characteristics. Overall, our study underlines the need for more comprehensive assessments in order to understand how diatom community composition is controlled by larger scale environmental variables in Arctic streams. [ABSTRACT FROM AUTHOR]

The work aims to probe the chances of utilizing the waste of pomegranate peel powder as a filler material alongside the polymer matrix. PVA is used as a polymer matrix in this study and the improvisation of its properties are the main objective by utilizing the pomegranate peel powder. By solution casting method, PVA/PP biocomposite films were prepared with varying weight % (0%, 5%, 10%, 15%, and 20%) of pomegranate peel powder and are examined with FTIR, XRD, morphological studies, thermal analysis, tensile property, antibacterial test, and degradation test. The biodegradable films' tensile strength was discovered to be 18.5 MPa, a 35% increase over films devoid of essential oil. The use of essential oil improved the thermal stability as well; the beginning degradation temperature increased by 40% to 210°C. Additionally, antimicrobial tests showed a 92% decrease in bacterial growth, demonstrating the essential oil's effectiveness as an antibacterial agent. In order to evaluate the barrier qualities of the films, water vapor permeability was tested. It was discovered that the water vapor transfer rate was 2.3 g/m2/day, demonstrating remarkable resistance to moisture permeability. The aforementioned tests indicate that the use of pomegranate peel powder and PVA in biocomposite films results in improved biodegradation, as well as antibacterial activity, and that can be utilized in various eco-friendly applications. In the same way, they show improved tensile as well as thermal properties which suggest the utilization as packaging materials. [ABSTRACT FROM AUTHOR]

The use of tetracyclines in medicine, veterinary medicine, and stock raising has led to the spread of bacterial resistance to tetracycline, particularly among dangerous representatives of Staphylococcus aureus. Therefore, the analysis of resistance to tetracycline and the creation of approaches to overcome it are extremely relevant. Studies of 64 clinical isolates of S. aureus, which were characterized by moderate biofilm formation, showed that 33 of them contained plasmid DNA. A significant spread (in 96% of studied isolates) of the known transmissible tetracycline resistance genes tet(K) and tet(M) was shown in the examined plasmid-containing doxycycline-resistant clinical isolates of S. aureus. Plasmid-containing doxycycline-resistant clinical isolates with tet(K) and tet(M) genes lost resistance to the tetracycline antibiotic doxycycline after treatment of their cells with gold nanoparticles of 30 nm in a concentration of 3.2–9.6 μg/mL or medium-sized silver of 30 nm in a concentration of 20–40 μg/mL. Elimination of tet genes responsible for acquired resistance was confirmed by PCR. [ABSTRACT FROM AUTHOR]

Listeria monocytogenes is a significant foodborne pathogen that can form biofilms on various food processing surfaces, thereby enhancing resistance to disinfectants and exacerbating harm to human health. Previous studies have indicated that bacteriocin BM173 exhibits antibacterial and antibiofilm activities. In the current study, our aim was to assess the inhibitory mode of action of sub-inhibitory concentrations (SICs, 1/32 × MIC and 1/16 × MIC) of BM173 on the biofilm formation L. monocytogenes. Crystal violet staining assay revealed that SICs of BM173 significantly inhibit L. monocytogenes biofilm formation. Furthermore, the results of swimming motility assay, plate count, ruthenium red staining, and scanning electron microscopy (SEM) revealed that SICs of BM173 could effectively reduce the movement, cell adhesion, and exopolysaccharide (EPS) production of L. monocytogenes, thereby inhibiting biofilm formation. Real-time quantitative PCR analyses further demonstrated that SICs of BM173 down-regulated the expression of biofilm-associated genes, including those encoding adhesion, virulence factors, and quorum sensing. Additionally, SICs of BM173 effectively reduced the biofilm formation of L. monocytogenes on the surfaces of three food-grade materials (glass, stainless steel, and silicone) at 4 and 25 °C. These outcomes suggest that BM173 holds great potential for development as a promising food preservative for application in the food industry. [ABSTRACT FROM AUTHOR]

Klebsiellapneumoniae is the most important species of the Klebsiella genus and often causes hospital infections. These bacteria have a high resistance to most of the available drugs, which has caused concern all over the world. In this study, we investigated the antibiotic resistance profile and the ability to produce extended-spectrum beta-lactamase (ESBL) among K. pneumoniae isolates, and then we investigated the relationship between these two factors with biofilm formation and the prevalence of different virulence genes. In this study, 130 isolates of K. pneumoniae isolated from wounds were investigated. The antibiotic resistance of the isolates was evaluated by the disk diffusion method. The microtiter plate method was used to measure biofilm formation. The prevalence of virulence genes was detected by multiplex PCR. Among the examined isolates, 85.3% showed multidrug resistance. 87.6% of the isolates were ESBL-positive. Imipenem, meropenem, and fosfomycin were the most effective drugs. The ability of the isolates to produce biofilm was strong (80%), moderate (12.3%), and weak (7.6%), respectively. fimH, mrKD, entB, and tolC virulence genes were observed in all isolates. High prevalence of antibiotic resistance (especially multidrug resistance), high prevalence of ESBL-producing isolates, the ability of all isolates to biofilm formation, and the presence of fimH, mrKD, entB, and tolC virulence genes in all isolates show the importance of these factors in the pathogenesis of K. pneumoniae isolates in Iraq. [ABSTRACT FROM AUTHOR]

Ruminiclostridium papyrosolvens is an anaerobic, mesophilic, and cellulolytic clostridia, promising consolidated bioprocessing (CBP) candidate for producing renewable green chemicals from cellulose, but its genetic transformation has been severely impeded by extracellular biofilm. Here, we analyzed the effects of five different inhibitors with gradient concentrations on R. papyrosolvens growth and biofilm formation. Gallic acid was proved to be a potent inhibitor of biofilm synthesis of R. papyrosolvens. Furthermore, the transformation efficiency of R. papyrosolvens was significantly increased when the cells were treated by the gallic acid, and the mutant strain was successfully obtained by the improved transformation method. Thus, inhibition of biofilm formation of R. papyrosolvens by using gallic acid will contribute to its genetic transformation and efficient metabolic engineering. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Staphylococcus aureus skin and soft tissue infection is a common ailment placing a large burden upon global healthcare infrastructure. These bacteria are growing increasingly recalcitrant to frontline antimicrobial therapeutics like vancomycin due to the prevalence of variant populations such as methicillin‐resistant and vancomycin‐resistant strains, and there is currently a dearth of novel antibiotics in production. Additionally, S. aureus has the capacity to hijack the host clotting machinery to generate fibrin‐based biofilms that confer protection from host antimicrobial mechanisms and antibiotic‐based therapies, enabling immune system evasion and significantly reducing antimicrobial efficacy. Emphasis is being placed on improving the effectiveness of therapeutics that are already commercially available through various means. Fibrin‐based nanoparticles (FBNs) were developed and found to interact with S. aureus through the clumping factor A (ClfA) fibrinogen receptor and directly integrate into the biofilm matrix. FBNs loaded with antimicrobials such as vancomycin enabled a targeted and sustained release of antibiotic that increased drug contact time and reduced the therapeutic dose required for eradicating the bacteria, both in vitro and in vivo. Collectively, these findings suggest that FBN‐antibiotic delivery may be a novel and potent therapeutic tool for the treatment of S. aureus biofilm infections. [ABSTRACT FROM AUTHOR]

Summary: Cryptococcosis is an invasive mycosis caused mainly by Cryptococcus gattii and C. neoformans and is treated with amphotericin B (AMB), fluconazole and 5-fluorocytosine. However, antifungal resistance, limited and toxic antifungal arsenal stimulate the search for therapeutic strategies such as drug repurposing. Among the repurposed drugs studied, the selective serotonin reuptake inhibitors (SSRIs) have shown activity against Cryptococcus spp. However, little is known about the antifungal effect of duloxetine hydrochloride (DH), a selective serotonin and norepinephrine reuptake inhibitor (SSNRI), against C. neoformans and C. gattii. In this study, DH inhibited the growth of several C. neoformans and C. gattii strains at concentrations ranging from 15.62 to 62.50 µg/mL. In addition, DH exhibited fungicidal activity ranging from 15.62 to 250 µg/mL. In biofilm, DH treatment reduced Cryptococcus spp. biomass at a level comparable to AMB, with a significant reduction (85%) for C. neoformans biofilms. The metabolic activity of C. neoformans and C. gattii biofilms decreased significantly (99%) after treatment with DH. Scanning electron micrographs confirmed the anti-biofilm activity of DH, as isolated cells could be observed after treatment. In conclusion, DH showed promising antifungal activity against planktonic cells and biofilms of C. neoformans and C. gattii, opening perspectives for further studies with DH in vivo. [ABSTRACT FROM AUTHOR]

Bacteria constitute the most abundant life form on earth, of which the majority exist in a protective biofilm state. Since the 1980s, we have learned much about the role of biofilm in human chronic infections, with associated global healthcare costs recently estimated at ~$386 billion. Chronic wound infection is a prominent biofilm‐induced condition that is characterised by persistent inflammation and associated host tissue destruction, and clinical signs that are distinct from signs of acute wound infection. Biofilm also enables greater tolerance to antimicrobial agents in chronic wound infections compared with acute wound infections. Given the difficulty in eliminating wound biofilm, a multi‐targeted strategy (namely biofilm‐based wound care) involving debridement and antimicrobial therapies were introduced and have been practiced since the early 2000s. More recently, acknowledgement of the speed at which biofilm can develop and hence quickly interfere with wound healing has highlighted the need for an early anti‐biofilm strategy to combat biofilm before it takes control and prevents wound healing. This strategy, referred to as wound hygiene, involves multiple tools in combination (debridement, cleansing, and antimicrobial dressings) to maximise success in biofilm removal and encourage wound healing. This review is intended to highlight the issues and challenges associated with biofilm‐induced chronic infections, and specifically address the challenges in chronic wound management, and tools required to combat biofilm and encourage wound healing. [ABSTRACT FROM AUTHOR]

Although typhoid fever has largely been eliminated in high-income countries, it remains a major global public health concern especially among low- and middle-income countries. The causative agent, Salmonella enterica serovar Typhi (S. Typhi), is a human restricted pathogen with a limited capacity to replicate outside the human host. Human carriers, 90% of whom have gallstones in their gallbladder, continue to shed the pathogen for an ill-defined period of time after treatment. The genetic mechanisms involved in establishing the carrier state are poorly understood, but S. Typhi is thought to undergo specific genetic changes within the gallbladder as an adaptive mechanism. In the current study, we aimed to identify the genetic differences in longitudinal clinical S. Typhi isolates from asymptomatic carriers with gallstones in a typhoid endemic setting in Nairobi, Kenya. Whole-genome sequences were analyzed from 22 S. Typhi isolates, 20 from stool samples, and 2 from blood samples, all genotype 4.3.1 (H58). Out of this, 19 strains were from four patients also diagnosed with gallstones, of whom three had typhoid symptoms and continued to shed S. Typhi after treatment. All isolates had point mutations in the quinolone resistance-determining region (QRDR), and only sub-lineage 4.3.1.2.EA3 encoded multidrug resistance genes. There was no variation in antimicrobial resistance patterns among strains from the same patient/household. Non-multidrug resistant (MDR) isolates formed significantly stronger biofilms in vitro than the MDR isolates, p<0.001. A point mutation within the treB gene (treB A383T) was observed in strains isolated after clinical resolution from patients living in 75% of the households. For missense mutations in Vi capsular polysaccharide genes, tviE P263S was also observed in 18% of the isolates. This study provides insights into the role of typhoid carriage, biofilm formation, AMR genes, and genetic variations in S. Typhi during asymptomatic carriage. [ABSTRACT FROM AUTHOR]

Biofilm is a structurally‐connected microbial community, covered by a self‐produced polymeric matrix and adhered to biotic or abiotic surfaces. This study aimed to evaluate the occurrence of biofilm‐producing antibiotic‐resistant bacteria in water from distribution systems. Water samples were taken from 32 tanks across Ondo City and Akure metropolis, Nigeria. Information regarding the sanitation status of the tanks was gathered by observation and oral interviews. The physicochemical properties were determined using standard methods. Using the pour plate technique. Agars included serially diluted water samples were inoculated onto plate count agar, mannitol salt agar, Salmonella-Shigella agar, MacConkey agar, and cetrimide nutrient agar to assess total viable bacteria, Staphylococcus aureus, Salmonella and Shigella, coliforms, and Pseudomonas aeruginosa, respectively. Eosin‐methylene blue agar was used to cultivate Escherichia coli and Enterobacter aerogenes. Pure isolates were characterised using API kits and assessed for antibiotic resistance and biofilm production employing the Kirby‐Bauer and tissue culture plate techniques, respectively. The ages of the water tanks ranged from 1 to 25 years old; all tanks had cover‐lids; 13 (40.63%) had water guards while 12 (37.5%) underwent water treatment. The physicochemical properties chiefly fell within WHO standards for drinking water. One hundred and eighty‐seven isolates were obtained. S. aureus (15.51%) had the highest frequency while Salmonella enterica (3.2%) had the lowest frequency. Thirty‐six percent of the isolates were strong biofilm producers, while 20.67% Gram‐negative and 18.69% Gram‐positive bacterial isolates were antibiotic‐resistant. This study revealed a high occurrence of biofilm‐forming bacteria and prevalence of antibiotic‐resistant bacteria in water distribution systems, emphasizing the urgency of improving water quality for public health protection. [ABSTRACT FROM AUTHOR]

Introduction: Bacteria have acquired resistance to almost all antibiotics currently in use due to their extensive, broad, and improper utilization over a prolonged period. DNA gyrase and DHFR exhibit significant promise as targets for antibacterial therapeutics. Methods: We have developed a series of disalicylic acid methylene/Schiff bases hybrids (6a-l) that function as antibacterial agents by targeting DNA gyrase and DHFR. Results and discussion: The findings showed that 6a-l have significant antibacterial activity against both Gram-positive and Gram-negative bacteria, with inhibition zones (IZ) comparable to or even higher than the reference Ciprofloxacin. MIC testing revealed that 6h and 6l were 1.5 times as effective than ciprofloxacin against S. aureus. Compounds 6h and 6l had MBC values of 28 and 33 nM for S. aureus , compared to Ciprofloxacin's 45 nM, indicating that they are more potent bactericidal agents. The MIC values for compounds 6c , 6e , 6h , 6j , and 6l against A. flavus were between 14.50 and 19.50 µM, while the MIC value for fluconazole was 11.50 µM. Also, the studied compounds had MIC values between 18.20 and 22.90 µM against C. albicans , while Fluconazole had a MIC value of 17.50 µM. Compound 6h showed a MIC value of 1.70 µM against the clinical strain S. aureus (ATCC 43300) (MRSA), making it an effective antibacterial agent. Compounds 6h , 6j , and 6l inhibited E. coli DNA gyrase with IC50 values of 79, 117, and 87 nM, respectively, compared to the reference novobiocin (IC50 = 170 nM). Additionally, compounds 6h and 6l , the most potent E. coli gyrase inhibitors, showed encouraging results on DHFR. Compounds 6h and 6l exhibit IC50 values of 3.80 µM and 4.25 µM, respectively. These values are significantly lower and hence more effective than Trimethoprim's IC50 of 5.20 µM. [ABSTRACT FROM AUTHOR]

ABSTRACT The current study aims to prepare a green extract using a new method in addition to conventional extraction methods including; methanolic and ultrasonic extraction of Salvia triloba, to compare their phenolic composition utilizing high‐performance liquid chromatograph equipped with a diode array detector (HPLC‐DAD), anti‐bacterial, anti‐oxidant, and enzyme inhibition activities. The results of HPLC‐DAD analysis showed that Rosmarinic acid was found the highest amount in the methanolic extract followed by ultrasonic and green extracts as 169.7 ± 0.51, 135.1 ± 0.40, and 28.58 ± 0.46 μg/g respectively. The Trans‐cinnamic acid (4.40 ± 0.09 μg/g) was found exclusively in ultrasonic extract. For bioactivities, the green extract exhibited the highest biofilm inhibition against Enterococcus faecalis compared to other extracts, while the methanolic extract outperformed both ultrasonic‐assisted and green extract against Staphylococcus aureus and Escherichia coli strains at minimum inhibitory concentration. The methanolic and green extract exhibited considerable quorum sensing inhibition against Chromobacterium violaceum CV026, while no activity was recorded from ultrasonic‐assisted extract. The methanolic and ultrasonic‐assisted extracts of S. triloba recorded moderate butyrylcholinesterase inhibition; each extract demonstrated limited inhibitory effects on the urease enzyme. Similarly, each extract of S. triloba demonstrated significant antioxidant activity, with the highest activity exhibited by methanolic extract as β‐carotene‐linoleic acid assay (IC50 = 10.29 ± 0.36 μg/mL), DPPH• assay (IC50 = 27.77 ± 0.55 μg/mL), ABTS•+ assay (IC50 = 15.49 ± 0.95 μg/mL), metal chelating assay (IC50 = 57.80 ± 0.95 μg/mL), and CUPRAC (assay A0.50 = 32.54 ± 0.84 μg/mL). Furthermore, the methanolic extract exhibited antioxidant activity better than α‐tocopherol (Standard used). The current study demonstrated the potential of green solvent(s) as eco‐friendly alternative for extractin phenolic compounds from S. triloba and evaluated their biological activities for the first time. [ABSTRACT FROM AUTHOR]

Thermophilic bacteria living in extreme areas with high temperatures are capable of producing secondary metabolites, such as antimicrobial peptides (AMPs). AMPs are stable at high temperatures and show good antibacterial activity. Therefore, this study aimed to identify thermophilic bacteria from the crater of Mount Tangkuban Perahu around West Java and assess antibacterial effectiveness of AMPs against Streptococcus mutans, which contribute to oral biofilm formation. The isolate obtained was identified using 16S ribosomal ribonucleic acid (rRNA) gene sequencing, and the supernatant of the isolate was tested against S. mutans American Type Culture Collection (ATCC) 25175 using the disc assay method. To determine AMPs‐coding genes, its genome was uploaded to antibiotic and secondary metabolite analysis shell (antiSMASH) 5.0.0 platform and biofilm inhibition was tested using the microtiter plate technique (with a 96‐well bottom). Subsequently, the results were assessed using a microplate reader operating at 595 nm wavelength. The isolate was identified as Geobacillus subterraneus, with antibacterial activity against S. mutans, and produced an inhibition zone of 8.40 mm at an optimum pH of 8. The output of AMPs‐coding gene showed that AMPs of the isolate were a member of the lanthipeptide class I, or bacteriocin‐I group. AMPs of G. subterraneus suppressed the growth of S. mutans biofilm at a supernatant concentration of 5%, with the lowest optical density (OD) value of 0.061 and the highest percentage of biofilm growth inhibition at 28.24%. Based on the results, G. subterraneus derived from the crater of Mount Tangkuban Perahu showed potent antibacterial properties against S. mutans, making it a promising novel S. mutans anti‐biofilm candidate. [ABSTRACT FROM AUTHOR]

Background: Enterohemorrhagic Escherichia coli (EHEC) O157 is implicated in serious food and water-borne diseases as hemorrhagic colitis (HC), and the potentially fatal hemolytic uremic syndrome (HUS). However, new players of non-O157 EHEC have been implicated in serious infections worldwide. This work aims at analyzing serotype and genotypic-based virulence profile of EHEC local isolates. Methods: A total of 335 samples were collected from different sources in Egypt. E. coli was isolated and subjected to serotyping. Non-O157 EHEC isolates were tested for virulence genes using PCR, phenotypic examination, phylogenetic typing, and molecular investigation by ERIC typing and MLST to disclose genetic relatedness of isolates. A heat map was used to identify potential associations between the origin of the isolates, their phenotypic and genotypic characteristics. Results: A total of 105 out of 335 isolates were identified as E. coli. Surprisingly, 49.5% of these isolates were EHEC, where O111, O91, O26 and O55 were the most prevalent serotypes including 38.46% from stool, 21.15% urine, 23.1% cheese, 9.62% meat products, 3.85% from both yogurt and sewage water. Screening 15 different virulence genes revealed that sheA, stx2 and eae were the most prevalent with abundance rates of 85%, 75% and 36%, respectively. Fifteen profiles of virulence gene association were identified, where the most abundant one was stx2/sheA (19%) followed by stx2/stx2g/sheA/eae (11.5%). Both stx2/sheA/eae and stx2/stx2g/sheA were equally distributed in 9.6% of total isolates. Phylogenetic typing revealed that pathogenic phylogroups B2 and D were detected among clinical isolates only. Forty-six different patterns were detected by ERIC genotyping. MLST resolved three sequence types of ST70, ST120 and ST394. The heat map showed that 21 isolates were of 70% similarity, 9 groups were of 100% clonality. Conclusions: The prevalence of non-O157 EHEC pathotype was marginally higher among the food isolates compared to the clinical ones. The endemic ST120 was detected in cheese, necessitating crucial measures to prevent the spread of this clone. Clinical EHEC isolates exhibited a higher score, and combination of virulence genes compared to food and sewage water isolates, thereby posing a significant public health concern. [ABSTRACT FROM AUTHOR]

Background: Although plastic pollution is increasing worldwide, very little is known about the microbial processes that take place once plastic debris is incorporated into the soil matrix. In this study, we conducted the first metatranscriptome analysis of polyethylene (PE)-associated biofilm communities in highly polluted landfill soil and compared their gene expression to that of a forest soil community within a 53-day period. Results: Our findings indicate that the microbial population present in soil contaminated with plastic debris is predisposed to both inhabit and degrade plastic surfaces. Surprisingly, the microbial community from undisturbed forest soil contained a diverse array of plastic-associated genes (PETase, alkB, etc.), indicating the presence of an enzymatic machinery capable of plastic degradation. Plastic-degrading taxa were upregulated in the early stages of biofilm formation. During the maturation of the biofilm, the alkB1/alkM transcripts, which encode PE-degrading enzymes, and transporters such as fadL, livG, livF, livH, and livM were upregulated, along with transcripts associated with the fatty acid β-oxidation pathway. Conclusions: In this study, we address the underlying patterns of gene expression during biofilm development in a PE-associated plastisphere in soil and address the pressing question of whether natural microbial communities have the potential to biodegrade petrochemical-based plastic in the soil environment. [ABSTRACT FROM AUTHOR]

AbstractBiofilms are microbial communities nested in self-secreted extracellular polymeric substances that can provide microorganisms with strong tolerance and a favorable living environment. Deepening the understanding and research on positive effects of microbial biofilms is consequently necessary, since most researches focuses on how to control biofilms formation to reduce food safety issues. This paper highlights beneficial roles of biofilms including the formation mechanism, influencing factors, health benefits, strategies to improve its film-forming efficiency, as well as applications especially in fields of food industry, agriculture and husbandry, and environmental management. Beneficial biofilms can be affected by multiple factors such as strain characteristics, media composition, signal molecules, and carrier materials. The biofilm barrier composed of beneficial bacteria provides a more favorable microecological environment, keeping bacteria survival longer, and its derived metabolites are better conducive to health. However, in the practical application of biofilms, there are still significant challenges, especially in terms of film-forming efficiency, stability, and safety assessment. Continuous research is needed to discover innovative methods of utilizing biofilms for sustainable food development in the future, in order to fully unleash its potential and promote its application in the food industry. [ABSTRACT FROM AUTHOR]

Trichosporon asahii, a dimorphic fungus, causes bloodstream infections in immunocompromised patients with neutropenia. Biofilms are formed on the surfaces of medical devices such as catheters as T. asahii transitions morphologically from yeast to hyphae in the host environment. Oxidative stress tolerance and morphological changes of T. asahii are regulated by Hog1, a mitogen-activated protein kinase. The role of Hog1 in the biofilm formation by T. asahii, however, has remained unknown. In the present study, we demonstrated that a hog1 gene-deficient T. asahii mutant formed excess biofilm under a rich medium in vitro, but did not form biofilm in an in vivo evaluation system using silkworms. The hog1 gene-deficient T. asahii mutant formed a greater amount of biofilm than the parent strain in vitro. Under an oxidative stress condition in vitro, however, lower amounts of biofilm were formed by the hog1 gene-deficient T. asahii mutant than by the parent strain. In an in vivo evaluation system using silkworms, lower amounts of biofilm were formed by the hog1 gene-deficient T. asahii mutant than by the parent strain. Our findings suggest that Hog1 regulates biofilm formation by T. asahii in response to host environmental conditions, including oxidative stress. [ABSTRACT FROM AUTHOR]

Plant diseases caused by soil-borne fungi and oomycetes significantly reduce yield and quality of many crops in the agricultural systems and are difficult to control. We herein examine Pseudomonas rhodesiae HAI-0804, a bacterial biological control agent that was originally developed for control of bacterial diseases on the surface of vegetables, and assessed its efficacy at controlling soil-borne diseases caused by oomycetes. Strain HAI-0804 did not exhibit detectable antibiotic activity toward Pythium ultimum , a causal agent of damping-off and root rot; however, it effectively protected against Pythium damping-off and root rot in cucumber. Exogenous glutamate enhanced the efficacy of biocontrol, the production of siderophore pyoverdine, root colonization in cucumber plants, and the ratio of biofilm formation to planktonic cells. The epiphytic fitness of strain HAI-0804 appears to contribute to plant protection efficacy against a broad spectrum of pathogens for both above-ground plant parts and the rhizosphere. [ABSTRACT FROM AUTHOR]