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Biofilm matrix
About: Biofilm matrix is a research topic. Over the lifetime, 1589 publications have been published within this topic receiving 110140 citations.
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TL;DR: Results of this study show that DNO2D strategy could significantly reduce H2S and CH4 emissions from sewers during the addition period but also suggest that microbial agents involved in such processes show a high resilience towards chemical stressors, thus favoring the re-establishment of H 2S andCH4 production after stopping nitrite addition.
31 citations
TL;DR: It is shown that FleQ of P. putida interacts with c-di-GMP and directly binds the promoter regions of flagellar and EPS genes, and a consensus sequence for promoter recognition by FleQ is also proposed.
31 citations
TL;DR: In this article, it was shown that in hydrodynamically grown biofilms, DeltavpsA and DeltaluxO mutants of Vibrio cholerae do not form pronounced, three-dimensional biofilm that resemble all aspects of wild-type bio-films.
Abstract: The natural life cycle of Vibrio cholerae involves the transitioning of cells between different environmental surfaces such as the chitinous shell of Crustaceae and the epithelial layer of the human intestine. Previous studies using static biofilm systems showed a strict dependence of biofilm formation on the vps and lux genes, which are essential for exopolysaccharide formation and cell-cell signaling, respectively. The authors' report here that in biofilms grown under hydrodynamic conditions, DeltavpsA and DeltaluxO mutants of V. cholerae do form pronounced, three-dimensional biofilms that resemble all aspects of wild-type biofilms. By genetic experiments, it was shown that in hydrodynamically grown biofilms this independence of vpsA is due to the expression of rpoS, which is a negative regulator of vpsA expression. Biofilms also underwent substantial dissolution after 96 h that could be induced by a simple stop of medium flow. The studies indicate that metabolic conditions control the reversible attachment of cells to the biofilm matrix and are key in regulating biofilm cell physiology via RpoS. Furthermore, the results redefine the roles of vps and quorum-sensing in V. cholerae biofilms.
31 citations
TL;DR: The aim of this study was to analyse the in vitro activity of farnesol alone and combined with the antibacterial drugs amoxicillin, doxycycline, ceftazidime and sulfamethoxazole–trimethoprim against Burkholderia pseudomallei biofilms.
Abstract: AIMS The aim of this study was to analyse the in vitro activity of farnesol alone and combined with the antibacterial drugs amoxicillin, doxycycline, ceftazidime and sulfamethoxazole-trimethoprim against Burkholderia pseudomallei biofilms. METHODS AND RESULTS Susceptibility was assessed by the broth microdilution test and cell viability was read with the oxidation-reduction indicator dye resazurin. The biofilms were evaluated through three microscopic techniques (optical, confocal and electronic microscopy). The minimum biofilm erradication concentration (MBEC) for farnesol was 75-2400 mmol l(-1). In addition, farnesol significantly reduced the MBEC values for ceftazidime, amoxicillin, doxycycline and sulfamethoxazole-trimethoprim by 256, 16, 4 and 4 times respectively (P < 0·05). Optical, confocal and electronic microscopic analyses of farnesol-treated B. pseudomallei biofilms demonstrated that this compound damages biofilm matrix, probably facilitating antimicrobial penetration in the biofilm structure. CONCLUSIONS This study demonstrated the effectiveness of farnesol against B. pseudomallei biofilms and its potentiating effect on the activity of antibacterial drugs, in particular ceftazidime, amoxicillin, doxycycline and sulfamethoxazole-trimethoprim. SIGNIFICANCE AND IMPACT OF THE STUDY The intrinsic antimicrobial resistance of B. pseudomallei is a serious challenge for the treatment of melioidosis. Thus, this paper reports the inhibitory potential of farnesol against B. pseudomallei biofilms, as well as highlights the favourable pharmacological interaction of farnesol with antibiotics tested, not only on cell viability, but also in the structural morphology of biofilms.
31 citations
Journal Article•
TL;DR: One-month long follow-up clinical trials have demonstrated that a maintenance solution of a 1:50 concentration of LA and sterile distilled water in self-contained dental units with new tubing is effective for prolonged periods in maintaining the effluent within the American Dental Association's recommendation for the year 2000 of < 200 CFU per ml.
Abstract: The problem of potential pathogens in biofilm within dental unit waterlines is real. Even though some chemical agents can disinfect biofilms, there remains concern that all remnants of the biofilm matrix are not eliminated, even with periodic treatments, and the bacterial populations in dental unit waterlines recur rapidly. Toxic and caustic residual chemicals are also a concern. In multiple trials following overnight treatment of dental unit waterlines with Listerine Antiseptic (LA), recurrence was investigated by evaluating effluent and biofilm specimens by plate culture. The presence or absence of biofilm within the dental unit waterlines was evaluated, pre- and post-treatment, by scanning electron microscopy. Baseline evaluations of dental unit waterlines determined the effluent and biofilm to harbor an average of 1 x 10(5) CFU per ml and 1 x 10(4) CFU per cm2, respectively, prior to treatment. Overnight, 18-hour treatment with LA rendered effluent and biofilm samples free of recoverable bacteria in all cases immediately following treatment. Viable bacteria in the effluent of treated dental unit waterlines recurred to near pre-treatment levels by Day 7. The minimum inhibitory concentrations for each of the recovered isolates did not change following overnight treatment. Repeated overnight treatments at the beginning of a one-week study were effective in inhibiting recurrence of viable bacteria in the biofilm and effluent indefinitely, but still failed to completely remove the biofilm matrix. New tubing treated prior to use and then daily with LA did not develop a detectable biofilm by scanning electron microscopy during the study. One-month long follow-up clinical trials have demonstrated that a maintenance solution of a 1:50 concentration of LA and sterile distilled water in self-contained dental units with new tubing is effective for prolonged periods in maintaining the effluent within the American Dental Association's recommendation for the year 2000 of < 200 CFU per ml. The clinical significance of these findings is that a solution to the problem of dental unit waterline contamination may be currently available. Since antimicrobial LA is safe for patient use, it may be one of the most viable options suggested to date.
31 citations