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Biofilms are complex communities of microorganisms that grow on surfaces and are embedded in a matrix of extracellular polymeric substances. These are prevalent in various natural and man-made environments, ranging from industrial settings to medical devices, where they can have both positive and negative impacts. This review explores the diverse applications of microbial biofilms, their clinical consequences, and alternative therapies targeting these resilient structures. We have discussed beneficial applications of microbial biofilms, including their role in wastewater treatment, bioremediation, food industries, agriculture, and biotechnology. Additionally, we have highlighted the mechanisms of biofilm formation and clinical consequences of biofilms in the context of human health. We have also focused on the association of biofilms with antibiotic resistance, chronic infections, and medical device-related infections. To overcome these challenges, alternative therapeutic strategies are explored. The review examines the potential of various antimicrobial agents, such as antimicrobial peptides, quorum-sensing inhibitors, phytoextracts, and nanoparticles, in targeting biofilms. Furthermore, we highlight the future directions for research in this area and the potential of phytotherapy for the prevention and treatment of biofilm-related infections in clinical settings.

leaf extract can mediate green synthesis of metal oxide nanoparticles with potential antimicrobial properties. This study evaluated copper oxide nanoparticles (CuO NPs) synthesized using for antifungal, antibiofilm, and cytocompatibility effects in a vaginal-simulant medium. CuO NPs were synthesized using leaf extract and characterized by FT-IR, XRD, UV-Vis, SEM, and EDX. 10 isolates and ATCC 90028 were screened for biofilm production; strong biofilm producers were selected for detailed testing. Antifungal activity (viability assays, MIC , MIC , MFC) and dose-response relationships were determined. Effects at sub-inhibitory concentrations on EPS production, cell-surface hydrophobicity, membrane permeability, ROS generation, germ tube formation, and biofilm formation/disruption were assessed. In vitro biocompatibility was evaluated by MTT assays on L929 fibroblasts, RAW 264.7 macrophages, MCF-12F epithelial cells, PBMCs, and by hemolysis assay. CuO NPs produced a concentration-dependent reduction in viability with high dose-response correlation = 0.967-0.9779). MIC , MIC , and MFC values ranged 44.5-103 µg/mL (ATCC 90028: MIC 44.5 µg/mL, MIC 86.5 µg/mL, MFC 91 µg/mL; 6: MIC 51.5 µg/mL, MIC 79.5 µg/mL, MFC 103 µg/mL). At sub-inhibitory concentrations, CuO NPs reduced EPS production and cell-surface hydrophobicity, increased membrane permeability and ROS generation, inhibited germ tube formation, and limited biofilm formation and integrity. Biocompatibility testing showed concentration-dependent cytotoxicity in fibroblasts and macrophages at higher doses, relative tolerance of MCF-12F cells, low hemolysis, and acceptable PBMC viability at lower concentrations. -mediated CuO NPs exhibit potent in vitro antifungal and antibiofilm activity against and affect multiple virulence-related pathways, with a distinguishable therapeutic window based on cell-type-dependent cytotoxicity. These findings support further development and optimization of topical intravaginal formulations of green-synthesized CuO NPs for candidal biofilm-associated infections, with additional in vivo safety and efficacy studies needed.

Mohammad Zubair, Email zmohammad@ut.edu.saIntroduction: Diabetic foot ulcers (DFUs) are a serious complication of diabetes, which is worsened by biofilm-forming bacterial infections that can contribute to antibiotic resistance and delayed wound healing. This study explores the antimicrobial and anti-biofilm properties of Ma’in Hot Springs Water (MHSW) against Staphylococcus aureus and Pseudomonas aeruginosa which are associated with DFU.Methods: The chemical composition of MHSW was determined using LC-MS, UV-Vis spectroscopy, and heavy metal profiling. Antimicrobial efficacy was determined through minimum inhibitory concentration (MIC) determination, bacterial growth kinetics, and biofilm inhibition assays.Results: The results demonstrated a dose-dependent antibacterial effect. Biofilm formation, exopolysaccharide production, and bacterial adhesion were reduced in treated samples. Moreover, MHSW disrupted virulence factors such as plasma coagulation and metallo-β-lactamase production. It was also found to be non-cytotoxic.Discussion: These findings demonstrate the potential of MHSW as an alternative or adjunctive treatment for DFU infections. However, the presence of heavy metals exceeding safety limits requires further investigation to determine their optimal concentration for clinical usage.

Background Bacillus cereus is implicated in severe foodborne infection in humans. This study intended to assess the occurrence, gro EL gene sequencing, biofilm production, and resistance profiles of emerged multidrug resistant (MDR) B. cereus in meat and meat product samples. Moreover, this work highlights the virulence and toxigenic genes ( hbl ABCD complex, nhe ABC complex, cyt K, ces , and pc-plc ) and antimicrobial resistance genes ( bla 1, tet A, bla 2, tet B, and erm A). Methods Consequently, 200 samples (sausage, minced meat, luncheon, beef meat, and liver; n  = 40 for each) were indiscriminately collected from commercial supermarkets in Port Said Province, Egypt, from March to May 2021. Subsequently, food samples were bacteriologically examined. The obtained isolates were tested for gro EL gene sequence analysis, antibiotic susceptibility, biofilm production, and PCR screening of toxigenic and resistance genes. Results The overall prevalence of B. cereus among the inspected food samples was 21%, where the highest predominance was detected in minced meat (42.5%), followed by beef meat (30%). The phylogenetic analysis of the gro EL gene exposed that the examined B. cereus strain disclosed a notable genetic identity with other strains from the USA and China. Moreover, the obtained B. cereus strains revealed β-hemolytic activity, and 88.1% of the recovered strains tested positive for biofilm production. PCR evidenced that the obtained B. cereus strains usually inherited the nhe complex genes ( nhe A and nhe C: 100%, and nhe B: 83.3%), followed by cyt K (76.2%), hbl complex ( hbl C and hbl D: 59.5%, hbl B: 16.6%, and hbl A: 11.9%), ces (54.7%), and pc-plc (30.9%) virulence genes. Likewise, 42.9% of the examined B. cereus strains were MDR to six antimicrobial classes and encoded bla 1, bla 2, erm A, and tet A genes. Conclusion In summary, this study highlights the presence of MDR B. cereus in meat and meat products, posing a significant public health risk. The contamination by B. cereus is common in minced meat and beef meat. The molecular assay is a reliable fundamental tool for screening emerging MDR B. cereus strains in meat and meat products.

The advent of nanotechnology has been instrumental in the development of new drugs with novel targets. Recently, metallic nanoparticles have emerged as potential candidates to combat the threat of drug-resistant infections. Diabetic foot ulcers (DFUs) are one of the dreadful complications of diabetes mellitus due to the colonization of numerous drug-resistant pathogenic microbes leading to biofilm formation. Biofilms are difficult to treat due to limited penetration and non-specificity of drugs. Therefore, in the current investigation, SnO 2 nanoparticles were biosynthesized using Artemisia vulgaris (AvTO-NPs) as a stabilizing agent and were characterized using ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Furthermore, the efficacy of AvTO-NPs against biofilms and virulence factors of drug-resistant Candida albicans strains isolated from DFUs was assessed. AvTO-NPs displayed minimum inhibitory concentrations (MICs) ranging from 1 mg/mL to 2 mg/mL against four strains of C. albicans. AvTO-NPs significantly inhibited biofilm formation by 54.8%–87%, germ tube formation by 72%–90%, cell surface hydrophobicity by 68.2%–82.8%, and exopolysaccharide (EPS) production by 69%–86.3% in the test strains at respective 1/2xMIC. Biosynthesized NPs were effective in disrupting established mature biofilms of test strains significantly. Elevated levels of reactive oxygen species (ROS) generation in the AvTO-NPs-treated C. albicans could be the possible cause of cell death leading to biofilm inhibition. The useful insights of the present study could be exploited in the current line of treatment to mitigate the threat of biofilm-related persistent DFUs and expedite wound healing.

Bacterial biofilms are closely associated with the rising threat of antimicrobial resistance, which is becoming a global concern. Recently, there has been increased interest in natural extracts as potential antimicrobial agents. One such extract is Dead Sea mud. While there is some evidence of its antimicrobial properties, it has not been extensively studied. Therefore, we designed a study to evaluate the potential of Dead Sea soil as an antimicrobial agent. For this purpose, three bacterial species (Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus) were isolated from the ulcerated foot of a patient in a hospital in Tabuk. P. aeruginosa exhibited significant antibiotic resistance, particularly to Levofloxacin (90%) and Tobramycin (80%), while S. aureus showed 70% resistance to Levofloxacin but no vancomycin resistance. Biofilm activity varied among bacterial strains, with P. aeruginosa showing 30% strong biofilm production. MIC values indicated resistance levels, with P. aeruginosa strain PA8 having the highest MIC at 650 µL/mL. All strains showed significant differences in exopolysaccharide (EPS) production at 0.25 × MIC (p ≤ 0.05) and 0.5 × MIC (p ≤ 0.005). Similarly, alginate production was significantly reduced at 0.25 × MIC (p ≤ 0.05), with even greater inhibition at 0.5 × MIC for combinations such as EC7 + SA5 (p ≤ 0.001). Hydrophobicity significantly changed at 0.25 × MIC (p ≤ 0.05), and combinations revealed highly significant reductions at 0.5 × MIC (p ≤ 0.001). Additionally, significant differences in outer membrane disruption were observed (p ≤ 0.05) with greater effects at 0.5 × MIC (p ≤ 0.005). Swarming motility was notably reduced for SA5 at 0.25 × MIC (p ≤ 0.05) and for PA2 at 0.5 × MIC (p ≤ 0.001). Chitinase activity showed greater reductions at 0.5 × MIC, with EC7 exhibiting the highest decrease. Lastly, sub-MIC concentrations enhanced reactive oxygen species (ROS) production, particularly for strains PA2 and SA5. Our results demonstrate the excellent potential of Dead Sea soil extract as an antimicrobial compound. Future studies should incorporate in vivo models to validate these findings clinically.

The hyper-cellulase producing bacterium Bacillus paramycoides strain BTH was isolated and characterized by 16S rRNA sequencing. Its potential for saccharification of Brachiaria mutica (para grass), a lignocellulosic aquatic weed, was examined. Cellulase production from strain BTH was enhanced by optimizing various parameters in the presence of goat dung as feedstock using One factor at a time (OFAT) and Response Surface Methodology (RSM) methods. The OFAT-based non-statistical method improved cellulase activity up to 1280.32±27.3 U/g. Box-Behnken Design of RSM-based optimization exhibited 1.3-fold enhancement in cellulase activity (1725.54±32.63 U/g) as compared to OFAT technique in the presence of goat dung medium (pH 8.0), incorporated with 1.5% (w/w) CMC and incubated at 37 °C. Para grass biomass was further pre-treated via hydrothermal, alkali, acid, hydrogen peroxide, and microwave heating methods and subjected to strain BTH-associated cellulase-based hydrolysis. The alkali pre-treated biomass exhibited maximum total reducing sugar production of 6.73±0.2, 9.25±0.16, 11.6±0.17, 14.11±0.16, and 11.54±0.16 mg/g in the presence of 4% (w/v) NaOH from 12 to 96 h. Likewise, 4% (w/v) NaOH pre-treated biomass showed maximum saccharification efficiency of 30.28±0.8, 41.62±0.6, 52.2±0.7, 63.49±0.6, and 51.93±0.8% from 12 to 96 h. The findings validated the role of B. paramycoides-associated cellulase in the saccharification of para grass.

The hyper-cellulase producing bacterium Bacillus paramycoides strain BTH was isolated and characterized by 16S rRNA sequencing. Its potential for saccharification of Brachiaria mutica (para grass), a lignocellulosic aquatic weed, was examined. Cellulase production from strain BTH was enhanced by optimizing various parameters in the presence of goat dung as feedstock using One factor at a time (OFAT) and Response Surface Methodology (RSM) methods. The OFAT-based non-statistical method improved cellulase activity up to 1280.32±27.3 U/g. Box-Behnken Design of RSM-based optimization exhibited 1.3-fold enhancement in cellulase activity (1725.54±32.63 U/g) as compared to OFAT technique in the presence of goat dung medium (pH 8.0), incorporated with 1.5% (w/w) CMC and incubated at 37°C. Para grass biomass was further pre-treated via hydrothermal, alkali, acid, hydrogen peroxide, and microwave heating methods and subjected to strain BTH-associated cellulase-based hydrolysis. The alkali pre-treated biomass exhibited maximum total reducing sugar production of 6.73±0.2, 9.25±0.16, 11.6±0.17, 14.11±0.16, and 11.54±0.16 mg/g in the presence of 4% (w/v) NaOH from 12 to 96 h. Likewise, 4% (w/v) NaOH pre-treated biomass showed maximum saccharification efficiency of 30.28±0.8, 41.62±0.6, 52.2±0.7, 63.49±0.6, and 51.93±0.8% from 12 to 96 h. The findings validated the role of B. paramycoides-associated cellulase in the saccharification of para grass.