This study aimed to develop and characterize sodium alginate (SA)/chitosan (CS) based nanoparticles (NPs), with or without morin or carvacrol, and to evaluate the antimicrobial and antibiofilm activity against polymicrobial oral biofilms. Three different NPs (0.15:1; 0.3:1; 0.5:1 CS:SA) whether or not containing morin or carvacrol were developed and characterized by particle size, zeta potential, scanning electron microscope (SEM), encapsulation efficiency, and drug release. NPs antibiofilm and antimicrobial activity were evaluated using polymicrobial oral biofilms by means of quantifying the biomass, assessment of viable microorganisms (CFU/mL), and acidogenicity of the biofilm by pH readings. The NPs presented nanometric size (<500 nm), with spherical shape and smooth surface. Encapsulation efficiency of the samples containing morin ranged from 46.17 to 55.15% and for carvacrol from 55.30 to 90.15%. Total release of carvacrol and morin occurred within 15 min. The NPs significantly reduced biofilm biomass and microbial viability compared to the control. However, did not significantly increase the biofilm pH. The NPs were effectively synthesized and showed antimicrobial and antibiofilm effect against oral biofilm and the addition of natural substances morin or carvacrol increased this effect. Combination of chitosan and sodium alginate and addition of morin or carvacrol in NPs can be a promising strategy for oral use, fighting biofilm and consequently biofilm dependent diseases.

and , key members of the ESKAPE group of hospital-acquired pathogens, are driving forces behind numerous infections due to their potent biofilm formation and the growing threat of antimicrobial resistance. Ferulic acid (FA) is known for its strong antioxidant properties and is recognized for its numerous physiological benefits, including anti-inflammatory, antimicrobial, anticancer, and antidiabetic effects. The current investigation delves into the antimicrobial and antibiofilm ability of FA against and . Using different assays, we confirmed that FA inhibits the biofilm formation of these pathogens. Through computational studies involving molecular docking and molecular dynamics simulations, it was found that FA exhibits a strong affinity for binding with MrkB in and MrkH in , crucial proteins involved in biofilm formation. We hypothesise that FA might interfere with adhesion-associated molecules and inhibit biofilms through the c-di-GMP pathway and proves as an effective antibiofilm compound.

The dairy industry faces challenges in controlling spoilage microorganisms, particularly , known to form resilient biofilms. Conventional disinfection methods have limitations, prompting the exploration of eco-friendly alternatives like ozone. This study focused on biofilms on polystyrene and polyethylene surfaces, evaluating ozone efficacy when incorporated into different water sources and applied under static and dynamic conditions. Biofilm formation and removal were assessed with conventional microbiological and microscopic techniques. Despite variations in physicochemical properties, ozonized water from different sources showed similar effectiveness in removing biofilms. Dynamic ozone application was more efficient, achieving a 2.35 log CFU/coupon reduction on polyethylene surfaces, compared to a 1.05 log CFU/coupon reduction under static conditions. These findings highlight the potential of ozonized water for removing biofilms, especially under dynamic application. This eco-friendly approach could serve as an effective strategy to mitigate biofilm-related challenges in the dairy industry.

Infections caused by multidrug-resistant pathogens, particularly in ICU settings, pose significant health risks globally. (PA) and methicillin-resistant (MRSA) are prominent nosocomial pathogens among the ESKAPE group, known for their resistance mechanisms such as biofilm formation and quorum sensing. Quercetin, a flavonoid found in fruits and vegetables, exhibits diverse pharmacological properties, including antimicrobial activity. This study evaluated quercetin's efficacy against PA and MRSA through and experiments. Minimum Inhibitory Concentration (MIC) assays showed MIC values of 158 µg mL for PA and 176 µg mL for MRSA. Quercetin inhibited PA's swarming motility at concentrations as low as 39.5 µg mL and reduced MRSA viability in serum by up to 79%. Quercetin treatment significantly reduced biofilm formation by both pathogens, with showing biomass reductions of 23% at 1/4 MIC (39.5 µg mL) and 48% at 1/2 MIC, while methicillin-resistant exhibited reductions of 27% at 1/4 MIC and 53% at 1/2 MIC compared to the control. High-content fluorescence imaging demonstrated quercetin's ability to disrupt biofilm structure and viability. Moreover, quercetin suppressed EPS production and protease activity in both PA and MRSA, alongside downregulating virulence-related genes involved in quorum sensing and toxin production. studies using confirmed quercetin's ability to reduce bacterial adherence and colonization. These findings underscore quercetin's potential as a therapeutic agent against multidrug-resistant pathogens in ICU settings, warranting further exploration for clinical applications.

Biofilms are a virulence factor for , a common pathogen in human fungal infections, making them resistant to many commercial antifungals. Therefore, the discovery of compounds that inhibit and eradicate biofilms is a priority. As thiosemicarbazones have had their effect on biofilms little explored, this study investigated the inhibitory and eradication activity of 30 thiosemicarbazones and analogues against biofilms. After initial screening, four compounds were selected and compound 28 emerged as the most potent with BIC at 31.55 ± 1.18 µM. By scanning electron microscopy analysis, blastoconidia adhered to the reduced surface and reduced formation of pseudohyphae and hyphae was revealed. Despite the inhibitory activity, the four compounds failed to eradicate the biofilm by more than 50%. Thus, the results suggest that the compounds evaluated are very promising for the development of effective antibiofilm compounds and open up new perspectives for elucidating the mechanism of action.

Histoplasmosis, caused by , poses risks for immunocompromised individuals. With limited therapeutic options, this study explores microparticles as antimicrobial delivery systems for and essential oils against . The broth microdilution assay showed MICs of 32 to 128 µg/mL in filamentous phase and 8 to 64 µg/mL in yeast phase. Combining microparticles with antifungal drugs demonstrated synergistic effects in both filamentous and yeast-like forms with amphotericin B or itraconazole. Chitosan microparticles reduced biofilm biomass and metabolic activity by about 60% at 512 µg/mL. evaluation with showed caused over 90% mortality. These findings highlight the potential use of chitosan microparticles as a delivery system for essential oils against , especially in combination with other compounds.

Biofilms are bacterial communities encapsulated in a self-produced extracellular polymeric matrix comprising carbohydrates, proteins, lipids, and DNA. This matrix provides structural integrity while significantly enhancing bacterial antibiotic resistance, presenting substantial disinfection challenges. The persistence of biofilm-associated infections and foodborne outbreaks underscores the need for more effective disinfection strategies. Conventional antibacterial agents often are less effective against biofilm-protected cells compared to their efficacy against planktonic (non-attached) bacteria. Integrating hydrolytic enzymes, such as cellulases, proteases, and DNases, into disinfection protocols offers a promising approach by breaking down the biofilm matrix to expose the bacteria. However, the follow-up use of antibacterial agents is important, as enzymes alone do not possess bactericidal properties. Unlike traditional disinfectants, natural antibacterial agents work synergistically with enzymes, enhancing biofilm disruption without compromising the enzymatic activity through oxidation. This review offers a comprehensive analysis of the current knowledge and potential of combining hydrolytic enzymes with disinfectants to disrupt biofilms and eradicate the released bacterial cells, emphasizing applications for clinical and foodborne pathogens.

In this study, we evaluated the impact of Epigalocatechin-3-gallate (EGCG) on biofilm development for 24 and 46 h using high-resolution confocal laser scanning microscopy. EGCG treatment led to the formation of interspaced exopolysaccharide (EPS)-microcolony complexes unevenly distributed on the surface of hydroxyapatite disc, forming a thinner and less complex biofilm structure with significantly reduced biomass, matrix volume, and thickness compared to the NaCl treated group (negative control). At 46 h, the biofilm of the EGCG-treatment group failed to form the bacterial-EPS superstructures which is characteristic of the biofilm in the negative control group. EGCG treatment seems to significantly delay biofilm development, with the 46 h biofilm in the EGCG treatment group resembling the negative control group at 24 h. EGCG topical treatments impaired biofilm initial growth and maturation, suggesting its potential to be used as a preventive agent against dental caries.

The efficacy of carbon dioxide (CO) to reduce biofouling by quagga mussels () in raw water systems was investigated. Experiments were conducted in a mobile laboratory located at Bureau of Reclamation Davis Dam Hydropower Facility and supplied with raw water from Lake Mohave, a reservoir of the Colorado River, USA. Incoming water was split between five chambers, each infused with CO at a different rate. Raw reservoir water containing quagga larvae (veligers) was mixed with CO chamber outflows and delivered to tanks containing settlement plates. Two experiments were conducted. Experiment 1 tested continuous infusion at target concentrations of 30, 45, 60, 75, and 100 mg L dCO (dissolved CO). Experiment 2 evaluated intermittent infusion schedules: 24 h on/off with 50, 75, and 100 mg L dCO and 24 h once/week with 100 mg L dCO. In Experiment 1, the percent settlement decreased with mean CO concentration, ranging from 5.0% to < 0.1% in 28.7 and 92.2 mg L dCO, respectively. In Experiment 2, the efficacy of 24 h on/off at dCO > 72.2 mg L was similar to continuous treatment. The least effective treatment was 24 h once weekly at 95 mg L dCO. These results demonstrate that CO treatment may reduce mussel biofouling in raw water systems.

Bacteria possess hair-like projections on their surface termed pili. The primary function of a pilus is to enable bacterial cell attachment to the host. Since pili are associated with cell adhesion, they play a major role in bacterial colonization and infection. Due to their important functional role, these surface appendages become ideal drug targets, hence it is essential to study the mechanism associated with pilus assembly, elongation, and attachment. Several enzymes are required for pilus biosynthesis, and their adhesion to the host. In this review paper, we have described the importance of the Sortase C (SrtC) protein which is required for pilus assembly and pilin polymerization. We also provide a detailed structural comparison of the protein from various pathogenic bacteria and highlight the importance of SrtC as a drug target. In addition to this, we have also reported structural studies of SrtC from the pathogenic bacteria using homology modelling.

Biofouling communities were examined at five depths at two salmon farms (Doctor Islets (DI), Wicklow Point (WP)) in British Columbia, Canada from April/May to October 2020. In addition, various water quality parameters were measured and the jellyfish numbers were quantified. Biofouling communities were mainly composed of Mollusca (primarily spp.), arthropods (mostly harpacticoids), and hydroids (predominantly sp.), while jellyfish samples were made up mostly of medusa-form sp. At DI, all variables except ammonia were associated with biofouling counts, all variables except depth were associated with hydroid biomass, while only temperature, dissolved oxygen, ammonia, and nitrate were associated with jellyfish. At WP, all variables except phosphate and silica were associated with biofouling counts, only depth was associated with hydroid biomass, and only ammonia was associated with jellyfish. Insights into what environmental variables are correlated with biofouling organisms and jellyfish may assist with the development of effective mitigation strategies.

biofilm is a significant virulence factor in infection. This study aimed to investigate antibacterial and antibiofilm activities of extract against . The MIC and MBC values of the extract against the isolates were 0.5-1.0 mg/mL. At 2 × MIC, the cells showed cell shrinkage and abnormalities. At 1/2 × MIC, the extract displayed 40-71% inhibition of biofilm formation. At 8 × MIC, the extract reduced the viability of mature biofilms by 60-86%. Hydroxychavicol and eugenol, the main compounds in the extract, showed binding activity to CdpA, an enzyme implicated in biofilms as observed by studies. Hydroxychavicol exhibited the highest affinity for CdpA, with a distance of 2.27 Å. Molecular dynamics simulations revealed that hydroxychavicol forms a stable complex with cyclic di-GMP phosphodiesterase, maintaining protein structural integrity with minimal conformational changes. The results suggested that may have medicinal benefits by inhibiting biofilm-related infections.

The efficacy of Zerumbone (ZER) against mixed biofilms of fluconazole-resistant (ATCC 96901) and (UA159) was evaluated. Biofilms were cultivated on acrylic resin specimens for 48 h, with alternating supplementation of glucose and sucrose. ZER's ability to inhibit biofilm formation (pre-treatment) and eradicate mature biofilms (post-treatment) was assessed. Control groups were treated with Chlorhexidine (CHX), Nystatin (NYS), Penicillin (ATB), and distilled water. The efficacy was measured by colony forming units (CFU/mm) counts, biomass and biofilm's matrix components quantification (water-soluble polysaccharides [WSP], alkali-soluble polysaccharides [ASPs], proteins, and extracellular DNA [eDNA]). Data were analyzed by one-way ANOVA with Tukey's or Gammes-Howell post-hoc test for normal data and Kruskal-Wallis test for data that did not meet the assumption of normality (α = 0,05). In the biofilm inhibition assay, ZER decreased total microbiota ( + ) (2.7 log;  < 0.005), (1.4 log;  < 0.038) and (1.9 log;  < 0.048) counting (vs control group), and biofilm components [insoluble proteins: 37% ( < 0.001); WSP: 13% ( < 0.042); ASP: 46% ( < 0.001); eDNA: 11% ( < 0.048)]. Post-treatment with ZER reduced total microbiota (3.2 log;  < 0.001), (3 log;  < 0.001) and (2 log;  < 0.001) counting (vs control group), and biofilm components [soluble proteins: 20% ( < 0.001); WSP: 20% ( < 0.001); ASP: 51% ( < 0.001); and eDNA: 33% ( < 0.001)]. The positive control groups demonstrated similar or lower efficacy than ZER under all experimental conditions. ZER demonstrates efficacy against mixed biofilms by reducing and counting and disrupting the extracellular matrix in both assays.

Compared to antimicrobial agents, anti-adhesive surfaces can reduce bacteria adhesion and biofilm formation in catheters, providing better selectivity, efficiency, and device life span. In this research, novel anionic surface biomaterials were created and tested to reduce microbial adhesion and colonization in medical device coating. Maleic anhydride (MA) was polymerized with 2-HEMA in varying amounts to produce a p(HEMA--MA) hydrogel copolymer. Fourier transforms infrared characterization (ATR-FTIR), thermal analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy, swelling capacity, cytotoxicity evaluation, and mixed biofilm formation ability were used to characterize the copolymer hydrogels. Hydrogels were evaluated by considering the guidance and regulations of ISO and ASTM standards. The polymers were dense, had stable cross-linking between both monomers, were non-toxic to the Human Embryonic Kidney (HEK) 293 cell line, and reduced bacterial biofilm formation statistically significantly. Furthermore, increasing the amount of MA affected gene expression, where the gene expression was significantly elevated, especially at the highest percentage of MA. Furthermore, the high percentage of MA in the polymer improved the new polymer's thermal properties, film flexibility, and swelling capacity. These novel polymers could be promising materials for improving catheter biomaterial properties and modifying the surfaces of designated devices to reduce microbial infections and growth.

The goal of this study was to evaluate if a magnetic water treatment device could be used to mitigate biofilms in water systems. Magnetic treatment was applied to water upstream of a modified Robbins device in which biofilms were formed. Duration of magnetic treatment, system flow rate, and field strength were varied to assess the impacts on the biofilm. A control system was concurrently established in which no magnetic treatment was applied. After treatment, the number of viable cells in the biofilm was reduced by up to 2.46 log CFU cm depending on the operational conditions. Increased cell stress, and ultimately death, was observed during treatment as indicated by an elevated AMPi stress index. These results indicate that magnetic water treatment may be an effective technology to decrease the extent of biofilms in water systems and a reduced need for chemical treatment. A mechanism is proposed in which metabolic processes are hindered due to the magnetic field effects on ions in the water. However, a mechanistic investigation remains outside the scope of this study. Future studies should aim to characterize both the impacts of treatment on the matrix and cellular processes to determine a mechanism for the observed effects.

is a pathogenic bacterium that can infect humans and animals, yet the role of its outer membrane vesicles (OMVs) in mediating pathogenicity remains underexplored. This study evaluated the effects of linoleic acid (LA) and stearic acid (SA) on quorum sensing (QS)-mediated violacein production, biofilm formation, and OMV biogenesis in . Our findings revealed that 2 mM LA and 1 mM SA effectively quench QS, leading to a significant reduction in violacein production, biofilm formation, and OMV biogenesis. Gene expression analysis confirmed the downregulation of QS-related genes, including , , , , and , in fatty acid-treated . Additionally, we assessed the antimicrobial activity of -derived OMVs on , a PGPR and observed a marked reduction in bactericidal activity in the treated OMVs. This study suggests that LA and SA have potential as anti-infective agents to mitigate OMV-mediated virulence and combat antibiotic resistance in pathogens.

This study hypothesizes that eugenol, due to its structural properties, can inhibit glucosyltransferase activity, thereby reducing polysaccharide synthesis in Typhimurium biofilms. It was found that eugenol exhibited minimum inhibitory and bactericidal concentrations of 0.6 mg mL and 0.8 mg mL, respectively, against planktonic Typhimurium growth. It also demonstrated minimum biofilm eradication and inhibition concentrations of 1.8 mg mL and 0.7 mg mL, respectively. At 0.3 mg mL, eugenol reduced biofilm formation and affected polysaccharide production. Moreover, eugenol reduced glucosyltransferase activity. Computational analysis indicated strong interactions between eugenol and the enzyme's active site residues with affinity energy -8.5 kcal mol. Real-time PCR revealed a significant increase in gene expression in the presence of eugenol. These findings suggest that eugenol's ability to inhibit glucosyltransferase activity effectively reduces biofilm formation and polysaccharide content.

Soft corals produce a diverse range of natural products with pharmaceutical potential, such as antiproliferative and anti-inflammatory effects. The Alcyoniidae family, particularly the genera and , is rich in bioactive terpenoids. However, despite extensive research, their anti-biofouling properties against the mussel remain underexplored. This study investigates these compounds as potential eco-friendly antifouling agents. A new cembrane-type diterpenoid, 11,12-epoxycembrene A (), and 15 known compounds were isolated from three soft corals distributed in Okinawa, Japan. The chemical structures of these secondary metabolites were elucidated based on spectroscopic analysis. Moreover, an anti-biofouling assay of potential anti-biofouling agents against was performed and their toxicities were assessed by means of the brine shrimp mortality test. In conclusion, this study identifies new and known bioactive compounds from soft corals, introduces an improved anti-biofouling assay, and highlights the potential of dimethylamine-containing diterpenes as environmentally friendly antifouling agents.

This work investigated the effect of () and () on the microbiologically influenced corrosion (MIC) behaviour of 70Cu-30Ni alloy using surface analysis and electrochemical techniques. The results demonstrated that the mixed medium containing and further accelerated the MIC of 70Cu-30Ni alloy compared to the single species medium. The addition of exogenous pyocyanin (PYO) to the medium increased the maximum pit depth on 70Cu-30Ni alloy from 5.40 μm to 6.59 μm, and the corrosion current density () increased by one order of magnitude. From the perspective of bioenergetics and extracellular electron transfer (EET), the comprehensive MIC mechanism of 70Cu-30Ni alloy induced by and was proposed.

This study aimed to investigate the effects of combined quercetin and antibiotics on the bacteriostatic activity and biofilm formation of . Optimal concentrations of quercetin and antibiotics (tetracycline and doxycycline) for inhibiting biofilm formation were determined using the Fractional Inhibitory Concentration Index and Minimum Biofilm Inhibitory Concentration assays. The impact of the drug combinations on biofilm clearance at various formation stages was determined using crystal violet staining, scanning electron microscopy and confocal laser microscopy. The results indicated that quercetin enhanced the bactericidal effect of tetracycline antibiotics against . The combination significantly reduced both the metabolic activity within biofilms and the production of biofilm matrix components. Scanning electron microscopy and confocal laser microscopy confirmed that the combination treatment significantly reduced bacterial cell counts within the biofilm. Quercetin treatment significantly increased the sensitivity of biofilms to antibiotics, supporting its potential application as a novel antibiotic synergist.

This study investigates the micro-topographic surfaces as a benign anti-fouling/fouling-release method. The bio-inspired engineered surfaces were manufactured by controlling the viscoelastic instabilities of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS) nanocomposites using a customized, scalable two-roll coating process. The effects of manufacturing conditions, i.e., roller speed and roller radius-to-gap ratio, on surface properties, such as Wenzel roughness factor, peak density, water contact angle, and the tensile testing of the nanocomposite, were studied. The results showed that decreasing roller gap distance would significantly increase the hydrophobicity of the samples. Moreover, a positive correlation was observed between surface peak density and roughness factor. A textured sample was manufactured that significantly outperformed the non-textured CNT-PDMS, indicating a correlation between surface roughness and diatom attachment density. The dynamic diatom attachment assay showed up to 35% reduction in surface coverage of textured samples by the diatom compared to the non-textured CNT-PDMS control samples.