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Biofilms are widespread in nature and constitute an important strategy implemented by microorganisms to survive in sometimes harsh environmental conditions. They can be beneficial or have a negative impact particularly when formed...
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Biofilms are widespread in nature and constitute an important strategy implemented by microorganisms to survive in sometimes harsh environmental conditions. They can be beneficial or have a negative impact particularly when formed in industrial settings or on medical devices. As such, research into the formation and elimination of biofilms is important for many disciplines. Several new methodologies have been recently developed for, or adapted to, biofilm studies that have contributed to deeper knowledge on biofilm physiology, structure and composition. In this review, traditional and cutting-edge methods to study biofilm biomass, viability, structure, composition and physiology are addressed. Moreover, as there is a lack of consensus among the diversity of techniques used to grow and study biofilms. This review intends to remedy this, by giving a critical perspective, highlighting the advantages and limitations of several methods. Accordingly, this review aims at helping scientists in finding the most appropriate and up-to-date methods to study their biofilms.
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Vibrio cholerae is a human pathogen and natural inhabitant of aquatic environments. Serogroups O1/O139 have been associated with epidemic cholera, while non-O1/non-O139 serogroups usually cause human disease other than classical c...
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Vibrio cholerae is a human pathogen and natural inhabitant of aquatic environments. Serogroups O1/O139 have been associated with epidemic cholera, while non-O1/non-O139 serogroups usually cause human disease other than classical cholera. V. cholerae non-O1/non-O139 from the Neusiedler See, a large Central European lake, have caused ear and wound infections, including one case of fatal septicaemia. Recent investigations demonstrated rapid planktonic growth of V. cholerae non-O1/non-O139 and correlation with zooplankton biomass. The aim of this study was to elucidate the interaction of autochthonous V. cholerae with two dominant crustacean zooplankton species in the lake and investigate the influence of the natural bacterial community on this interaction. An existing data set was evaluated for statistical relationships between zooplankton species and V. cholerae and co-culture experiments were performed in the laboratory. A new fluorescence in situ hybridisation protocol was applied for quantification of V. cholerae non-O1/non-O139 cells, which significantly reduced analysis time. The experiments clearly demonstrated a significant relationship of autochthonous V. cholerae non-O1/non-O139 with cladocerans by promoting growth of V. cholerae non-O1/non-O139 in the water and on the surfaces of the cladocerans. In contrast, copepods had a negative effect on the growth of V. cholerae non-O1/non-O139 via competing bacteria from their surfaces. Thus, beside other known factors, biofilm formation by V. cholerae on crustacean zooplankton appears to be zooplankton taxon specific and may be controlled by the natural bacterial community.
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Biofilm formation is the leading cause of the pathogenesis of S. aureus associated with biomaterial infections. In S. aureus polysaccharide intercellular adhesin (PIA) was encoded by icaA and icaD genes. Production of PIA is curre...
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Biofilm formation is the leading cause of the pathogenesis of S. aureus associated with biomaterial infections. In S. aureus polysaccharide intercellular adhesin (PIA) was encoded by icaA and icaD genes. Production of PIA is currently responsible for staphylococcal biofilm development. In this study, S. aureus strains isolated from auricular infection (n = 46) and S. aureus ATCC 25923 were phenotyped and genotyped. Slime production was assessed using Congo red agar plate assay. In order to determine the biofilm formation capacity at various pH levels of the studied S. aureus strains, microtiter plate assay was performed. The strains were grown in medium adjusted at various pH levels (3, 5, 7, 9 and 12) and medium supplemented with hydrogen peroxide 3% (v/v). Qualitative biofilm production of S. aureus revealed that 56.5% of strains were slime producers. In addition 78.26% of strains were icaA and icaD positive. Quantitative biofilm showed that biofilm production depended on the pH value of the medium. At highly acidic (pH 3) and alkaline (pH 12) levels, biofilm formation was lower, while at pH 7 the adhesion was moderate. In addition, the cells adhered weakly after 3% hydrogen peroxide supplementation. Our results suggest that pH was a stress factor that led some S. amens strains to produce the biofilm.
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The discovery of biofilm formation in bacteria and yeasts has led to a better understanding of microbial ecology and to new insights into the mechanisms of virulence and persistence of pathogenic microorganisms. However, it is gen...
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The discovery of biofilm formation in bacteria and yeasts has led to a better understanding of microbial ecology and to new insights into the mechanisms of virulence and persistence of pathogenic microorganisms. However, it is generally assumed that filamentous fungi, some of which have a significant impact on our health or our economy, do not form biofilms. In contrast to this assumption, here we discuss recent findings supporting the hypothesis that surface-associated filamentous fungi can form biofilms. Based on these findings and on previous models for bacterial and yeast systems, we propose preliminary criteria and a model for biofilm formation by filamentous fungi.
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Biofilms in the environment can both cause detrimental and beneficial effects. However, their use in bioreactors provides many advantages including lesser tendencies to develop membrane fouling and lower required capital costs, th...
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Biofilms in the environment can both cause detrimental and beneficial effects. However, their use in bioreactors provides many advantages including lesser tendencies to develop membrane fouling and lower required capital costs, their higher biomass density and operation stability, contribution to resistance of microorganisms, etc. Biofilm formation occurs naturally by the attachment of microbial cells to the support without use of any chemicals agent in biofilm reactors. Biofilm reactors have been studied and commercially used for waste water treatment and bench and pilot-scale production of value-added products in the past decades. It is important to understand the fundamentals of biofilm formation, physical and chemical properties of a biofilm matrix to run the biofilm reactor at optimum conditions. This review includes the principles of biofilm formation; properties of a biofilm matrix and their roles in the biofilm formation; factors that improve the biofilm formation, such as support materials; advantages and disadvantages of biofilm reactors; and industrial applications of biofilm reactors.
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摘要 :
Biofilms in the environment can both cause detrimental and beneficial effects. However, their use in bioreactors provides many advantages including lesser tendencies to develop membrane fouling and lower required capital costs, th...
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Biofilms in the environment can both cause detrimental and beneficial effects. However, their use in bioreactors provides many advantages including lesser tendencies to develop membrane fouling and lower required capital costs, their higher biomass density and operation stability, contribution to resistance of microorganisms, etc. Biofilm formation occurs naturally by the attachment of microbial cells to the support without use of any chemicals agent in biofilm reactors. Biofilm reactors have been studied and commercially used for waste water treatment and bench and pilot-scale production of value-added products in the past decades. It is important to understand the fundamentals of biofilm formation, physical and chemical properties of a biofilm matrix to run the biofilm reactor at optimum conditions. This review includes the principles of biofilm formation; properties of a biofilm matrix and their roles in the biofilm formation; factors that improve the biofilm formation, such as support materials; advantages and disadvantages of biofilm reactors; and industrial applications of biofilm reactors.
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The possible presence of biofilms was examined in mucosal specimens of 15 patients, undergoing functional endoscopic sinus surgery or a modified Caldwell-Luc approach for chronic rhinosinusitis (CRS). Biofilms were found in 7 of t...
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The possible presence of biofilms was examined in mucosal specimens of 15 patients, undergoing functional endoscopic sinus surgery or a modified Caldwell-Luc approach for chronic rhinosinusitis (CRS). Biofilms were found in 7 of the 15 patients, positive cultures being obtained in most samples, which supports the role of biofilms as an important factor in the pathogenesis of CRS.
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Mesh hernioplasty is among the most frequently performed surgical procedures. The introduction of mesh implants has decreased recurrence rates, but the use of synthetic materials carries the risk of infection and biofilm formation...
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Mesh hernioplasty is among the most frequently performed surgical procedures. The introduction of mesh implants has decreased recurrence rates, but the use of synthetic materials carries the risk of infection and biofilm formation. This paper presents the course of the disease in the case of biofilm formation on the surface of an implanted surgical mesh. Antimicrobial therapy and partial removal of the implant were unsuccessful. Recurring surgical site infection could be managed only through total excision of the infected implant.
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Mycoplasma gallisepticum is the causative agent of chronic respiratory disease in chickens and of infectious sinusitis in turkeys, chickens, game birds, pigeons, and passerine birds of all ages. This study investigated the biofilm...
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Mycoplasma gallisepticum is the causative agent of chronic respiratory disease in chickens and of infectious sinusitis in turkeys, chickens, game birds, pigeons, and passerine birds of all ages. This study investigated the biofilm-producing ability of M. gallisepticum strains in an attempt to explain its intriguing persistence in commercial flocks. Eleven strains of M. gallisepticum were investigated for their biofilm formation, which varied considerably. Strains Nobilis MG 6/85, S-6 (P-5 and P-20), D-9604, and SU15 were strong biofilm producers. Strains R-low (P-10 and P-100), NCL, CG(5), YL4, and F were weak biofilm producers. Strains Vaxsafe MG ts-11 and F-36 did not produce biofilm as verified using a crystal violet staining assay. In addition, highly differentiated biofilm structures of strain Nobilis MG 6/85 with characteristic stacks and channels were observed under confocal scanning laser microscopy and scanning electron microscopy. The carbohydrates (sucrose, glucose), disodium ethylenediaminetetraacetic acid (EDTA), antibiotics (tetracycline, gentamicin), or detergent (Triton X-100) were further used to determine their effects on biofilm formation. Biofilm formation was significantly inhibited by 5% sucrose and 5 mmol/L EDTA. Compared with the planktonic mycoplasma, these biofilm-grown cultures were more resistant to tetracycline, gentamicin, and Triton X-100 treatments. Furthermore, real-time reverse transcriptase-polymerase chain reaction was performed to investigate the transcription of several genes that may be associated with biofilm formation. The results indicated that the transcriptions of some genes in the biofilm-grown cells were markedly decreased, including vlhA3.03, csmC, hatA, gapA, neuraminidase, and mgc2. Our results will benefit further research on the persistence of M. gallisepticum infections. (C) 2012 Elsevier B.V. All rights reserved.
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This study aims to explore the potential targets of bithionol in Staphylococcus aureus.The four bithionol biotinylated probes Bio-A2-1, Bio-A2-2, Bio-A2-3, and Bio-A2-4 were synthesized, the minimal inhibitory concentrations (MICs...
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This study aims to explore the potential targets of bithionol in Staphylococcus aureus.The four bithionol biotinylated probes Bio-A2-1, Bio-A2-2, Bio-A2-3, and Bio-A2-4 were synthesized, the minimal inhibitory concentrations (MICs) of these probes against S. aureus were determined. The bithionol binding proteins in S. aureus were identified through immunoprecipitation and LC-MS/MS with bithionol biotinylated probe. The biotinylated bithionol probes Bio-A2-1 and Bio-A2-3 displayed antibacterial activities against S. aureus. The Bio-A2-1 showed lower MICs than Bio-A2-3, and both with the MIC50/MIC90 at 12.5/12.5 mu M against S. aureus clinical isolates. The inhibition rates of bithionol biotinylated probes Bio-A2-1 and Bio-A2-3 on the biofilm formation of S. aureus were comparable to that of bithionol, and were stronger than that of Bio-A2-2 and Bio-A2-4. The biofilm formation of 10 out of 12S. aureus clinical isolates could be inhibited by Bio-A2-1 (at 1/4x, or 1/2x MICs). There are three proteins identified in S. aureus through immunoprecipitation and LC-MS/MS with bithionol biotinylated probe Bio-A2-1: Protein translocase subunit SecA 1 (secA1), Alanine--tRNA ligase (alaS) and DNA gyrase subunit A (gyrA), and in which the SecA1 protein the highest coverage and the most unique peptides. The LYS112, GLN143, ASP213, GLY496 and ASP498 of SecA1 protein act as hydrogen acceptors to form 6 hydrogen bonds with bithionol biotinylated probe Bio-A2-1 by molecular docking analysis. In conclusion, the bithionol biotinylated probe Bio-A2-1 has antibacterial and anti-biofilm activities against S. aureus, and SecA1 was probably one of the potential targets of bithionol in S. aureus.
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