Biofouling最新文献

Candida auris is a multidrug-resistant yeast that has seen a worrying increase during the COVID-19 pandemic. Give7/n this, new therapeutic options, such as controlled-release nanomaterials, may be promising in combating the infection. Therefore, this study aimed to develop amphotericin B (AmB) and micafungin (MICA)-loaded nanoemulsions (NEMA) and evaluated against biofilms of C. auris. Nanoemulsions (NEs) were characterized and determined minimum inhibitory concentration MIC₉₀, checkerboard and anti-biofilm. NEMA presented a size of 53.7 and 81.4 nm for DLS and NTA, respectively, with good stability and spherical morphology. MICAmB incorporated efficiency was 88.4 and 99.3%, respectively. The release results show that AmB and MICA obtained a release of 100 and 63.4%, respectively. MICAmB and NEMA showed MIC90 values of 0.015 and 0.031 ug/mL, respectively and synergism. NEMA showed greater metabolic inhibition and morphological changes in mature biofilms. This drugs combination and co-encapsulation proved to be a promising therapy against C. auris biofilms.

Efflux pump inhibitors are a potential therapeutic strategy for managing antimicrobial resistance and biofilm formation. This article evaluated the effect of carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on the biofilm growth dynamics and the production of virulence factors by Burkholderia pseudomallei. The effects of CCCP on planktonic, growing, and mature biofilm, interaction with antibacterial drugs, and protease and siderophore production were assessed. CCCP MICs ranged between 128 and 256 µM. The CCCP (128 µM) had a synergic effect with all the antibiotics tested against biofilms. Additionally, CCCP reduced (p < .05) the biomass of biofilm growth and mature biofilms at 128 and 512 µM, respectively. CCCP also decreased (p < .05) protease production by growing (128 µM) and induced (p < .05) siderophore release by planktonic cells (128 µM) growing biofilms (12.8 and 128 µM) and mature biofilms (512 µM). CCCP demonstrates potential as a therapeutic adjuvant for disassembling B. pseudomallei biofilms and enhancing drug penetration.

Using existing adrentimicrobials with essential oil components to prevent antimicrobial resistance is an alternative strategy. This study aimed to evaluate the resistance status, synergistic combinations, and in vitro biofilm formation activities of clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), Stenotrophomonas maltophilia and Candida albicans against antimicrobial agents and cinnamaldehyde, carvacrol, eugenol, limonene and eucalyptol. Antimicrobial activities were evaluated by microdilution, cytotoxicity by XTT, synergy by checkerboard and time-kill, and biofilm inhibition by microplate methods. Cinnamaldehyde and carvacrol showed strong antimicrobial activity. Synergistic effects were observed when using all essential oils with antimicrobials. Only two C. albicans isolates showed antagonism with cinnamaldehyde and fluconazole. The constituents showed cytotoxic effects in the L929 cell line (except limonene). A time-kill analysis revealed a bacteriostatic effect on S. maltophilia and MRSA isolates and a fungicidal effect on C. albicans isolates. These results are important for further research to improve antimicrobial efficacy or to develop new agents.

Polyethylene terephthalate (PET) and polylactic acid (PLA) are among the polymers used in the food industry. In this study, crude extracts of Dunaliella salina were used to treat the surface of 3D printed materials studied, aiming to provide them with an anti-adhesive property against Pseudomonas aeruginosa. The hydrophobicity of treated and untreated surfaces was characterized using the contact angle method. Furthermore, the adhesive behavior of P. aeruginosa toward the substrata surfaces was also studied theoretically and experimentally. The results showed that the untreated PLA was hydrophobic, while the untreated PET was hydrophilic. It was also found that the treated materials became hydrophilic and electron-donating. The total energy of adhesion revealed that P. aeruginosa adhesion was theoretically favorable on untreated materials, while it was unfavorable on treated ones. Moreover, the experimental data proved that the adhesion to untreated substrata was obtained, while there was complete inhibition of adhesion to treated surfaces.

Understanding factors influencing Listeria monocytogenes biofilms aid in developing more effective elimination/prevention strategies. This study examined the effect of temperature (4 °C, 21 °C, 30 °C), materials (stainless steel 316 L with 2B and 2 R finishes, glass, and polypropylene), and slope (0°/horizontal or 90°/vertical) on mono- and dual-species biofilms using two L. monocytogenes strains and one Pseudomonas aeruginosa strain. All biofilms were grown in 10% TSB for 24 h and analyzed using culture-based methods. Additionally, the architecture of monospecies biofilms was studied using fluorescence microscopy. Overall, P. aeruginosa showed higher biofilm formation potential (6.2 log CFU/cm²) than L. monocytogenes (4.0 log CFU/cm²). Temperature greatly influenced P. aeruginosa and varied for L. monocytogenes. The slope predominantly influenced L. monocytogenes monospecies biofilms, with cell counts increasing by up to 2 log CFU/cm². Surface material had little impact on biofilm formation. The study highlights the varying effects of different parameters on multispecies biofilms and the importance of surface geometry.

Candida albicans invasive candidiasis is considered a global health problem. In such cases, biofilm formation on implanted devices represents a therapeutic challenge and the presence of metabolically inactive persistent cells (PCs) in these communities increases their tolerance to fungicidal drugs. This study investigated the influence of amoxicillin, AMX; cefepime, CEF; gentamicin, GEN; amikacin, AMK; vancomycin, VAN; and ciprofloxacin, CIP; on the production of PCs in biofilms of C. albicans bloodstream isolates. 48 h-mature biofilms (n = 6) grown in RPMI-1640 supplemented with antibiotics were treated with 100 μg ml^-1 amphotericin B and then evaluated for PCs. Biofilms grown in the presence of antibiotics produced more PCs, up to 10×, when exposed to AMX and CIP; 5 × to CEF; and 6 × to GEN and VAN. The results indicate that antibiotics can modulate PC production in C. albicans biofilms. This scenario may have clinical repercussions in immunocompromised patients under broad-spectrum antibiotic therapy.

The bacterial community from a cooling water system was investigated through culture-dependent and independent strategies, and the responses of planktonic and sessile bacteria (grown in glass slides and stainless-steel coupons) to antimicrobials of industrial and clinical use were assessed. The morphotypes with higher biofilm-forming potential were Pseudoxanthomonas sp., Rheinheimera sp., Aeromonas sp. and Staphylococcus sp., and the first also exhibited lower susceptibility to all antibiotics and biocides tested. 16S rRNA high throughput sequencing indicated that Pseudomonadota (77.1% on average, sd 11.1%), Bacteroidota (8.4, sd 5.7%), and Planctomycetota (3.0, sd 1.3%) were the most abundant phyla. KEGG orthologs associated with antibiotics and biocide resistance were abundant in all samples. Although the minimum inhibitory and bactericidal concentrations were generally higher for biofilms, morphotypes in planktonic form also showed high levels of resistance, which could be associated with biofilm cells passing into the planktonic phase. Overall, monochloramine was the most effective biocide.

This case study aimed to isolate and identify methanogenic bacteria from landfill soil, mud, and leachate samples to assess their role in anaerobic digestion and biogas production. Anaerobic digestion involves the breakdown of organic matter by a diverse group of bacteria under oxygen-free conditions, resulting in the production of methane and carbon dioxide. The collected samples from the landfill were cultured in a modified mineral salt medium (MSM). Microscopic observations revealed distinct coccus and bacillus morphologies of the isolated methanogenic bacteria. Gas production experiments and substrate utilization studies identified two types of methanogens. Methanosarcina sp., which utilized acetate and methanol for methane production, and Methanobacterium sp., utilizing hydrogen and carbon dioxide, as well as acetate. Scanning electron microscope (SEM) analysis confirmed the different morphotypes of the isolated methanogens. The study findings demonstrated the presence of diverse methanogens in the landfill environment, contributing to anaerobic digestion and biogas production.