Topic
Biofilm
About: Biofilm is a research topic. Over the lifetime, 23010 publications have been published within this topic receiving 906812 citations. The topic is also known as: biofilms.
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TL;DR: It appears that cellular properties such as growth differentiation, chemotaxis, and cell-to-cell signaling enable biofilm communities to organize structurally in response to the external conditions and the activities of the different biofilm members.
Abstract: The application of advanced microscopy and molecular and electrochemical high-resolution methods has provided insights into the structural organization and function of biofilm communities. It appears that cellular properties such as growth differentiation, chemotaxis, and cell-to-cell signaling enable biofilm communities to organize structurally in response to the external conditions and the activities of the different biofilm members. Thereby resource utilization becomes optimized, and processes which require syntrophic relationships or special micro-environments become facilitated.
298 citations
TL;DR: Chronic rhinosinusitis is a common disease poorly controlled by antibiotics and postulated etiologies include allergy, fungi, functional factors, and biofilm.
Abstract: Introduction: Chronic rhinosinusitis (CRS) is a common disease poorly controlled by antibiotics. Postulated etiologies of CRS include allergy, fungi, functional factors, and biofilm. Objectives: We presented a preliminary study demonstrating bacterial biofilms' presence on the sinus mucosa of patients with CRS using fluorescent in situ hybridization (FISH). The advantage of FISH in biofilm identification is that it is the only method that identifies the specific bacteria creating the biofilm matrix. We now present the results of a larger series of patients. Methods: Patients with CRS scheduled for sinus surgery were enrolled in the study. Biopsies of the sinus mucosa and cultures were taken at the time of surgery. Control samples were taken from patients undergoing septoplasty. Specimens underwent FISH testing for Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenza, and Pseudomonas aeruginosa. Results: Bacterial biofilms were present on 14 of 18 specimens. The predominant species were H. influenzae, S. pneumoniae, and S. aureus. P. aeruginosa biofilm was not identified on any specimens. The intraoperative cultures of the planktonic bacteria present in the sinuses did not correlate with the biofilms identified. Two of the five control samples were positive for biofilm. Conclusion: The presence of biofilms on the mucosa of patients with CRS offers a possible cause of antimicrobial therapy failure and could change the approach to treatment. However, the presence of biofilms on healthy control samples implies that biofilms may simply be colonizers. The precise role that biofilms play in CRS still remains to be determined. Further studies with larger sample sizes are needed.
298 citations
TL;DR: The results indicate that high levels of initial adherence do not necessarily lead to thick biofilm formation and the two aspects of the pathogenesis of medical device related-infection may need to be evaluated independently to ascertain the contribution of each to the virulence of S. epidermidis causing device-related infections.
298 citations
TL;DR: Cold-shock protein transcriptional regulators (cspABFGI) appear to be positive biofilm regulators, and deletions in respiratory genes (e.g. gatZABCDR, agaBCY) were highly regulated in biofilms.
Abstract: Analysis of the temporal development of Escherichia coli K-12 biofilms in complex medium indicates the greatest differential gene expression between biofilm and suspension cells occurred in young biofilms at 4 and 7 h (versus 15 and 24 h). The main classes of genes differentially expressed (biofilm versus biofilm and biofilm versus suspension cells) include 42 related to stress response (e.g. cspABFGI), 66 related to quorum sensing (e.g. ydgG, gadABC, hdeABD), 20 related to motility (e.g. flgBCEFH, fliLMQR, motB), 13 related to fimbriae (e.g. sfmCHM, fimZ, csgC), 24 related to sulfur and tryptophan metabolism (e.g. trpLBA, tnaLA, cysDNCJH), 80 related to transport (e.g. gatABC, agaBC, ycjJ, ydfJ, phoU, phnCJKM), and six related to extracellular matrix (e.g. wcaBDEC). Of the 93 mutants identified and studied, 76 showed altered biofilm formation. Biofilm architecture changed from thin and dense to globular and dispersed to dense and smooth. The quorum-sensing signal AI-2 controls gene expression most clearly in mature biofilms (24 h) when intracellular AI-2 levels are highest. Sulfate transport and metabolism genes (cysAUWDN) and genes with unknown functions (ymgABCZ) were repressed in young (4, 7 h) biofilms, induced in developed biofilms (15 h), and repressed in mature (24 h) biofilms. Genes related to both motility and fimbriae were induced in biofilms at all sampling time points and colanic acid genes were induced in mature biofilms (24 h). Genes related to dihydroxyacetone phosphate synthesis from galactitol and galactosamine (e.g. gatZABCDR, agaBCY) were highly regulated in biofilms. Genes involved in the biosynthesis of indole and sulfide (tnaLA) are repressed in biofilms after 7 h (corroborated by decreasing intracellular indole concentrations in biofilms). Cold-shock protein transcriptional regulators (cspABFGI) appear to be positive biofilm regulators, and deletions in respiratory genes (e.g. hyaACD, hyfCG, appC, narG) increased biofilm formation sevenfold.
298 citations
TL;DR: Results indicate that the structure of a C. albicans biofilm depends on the nature of the contact surface, but that some surfaces produce biofilms with a layered architecture resembling to that described for bacterial systems.
Abstract: Two model biofilm systems, involving growth on disks of catheter material or on cylindrical cellulose filters, were used to investigate the structure of Candida albicans biofilms To assess the importance of dimorphism in biofilm development, biofilms produced by two wild-type strains were compared with those formed by two morphological mutants, incapable of yeast and hyphal growth, respectively Scanning electron microscopy and thin sections of biofilms examined by light microscopy revealed that biofilms of the wild-type strains formed on catheter disks consisted of two distinct layers: a thin, basal yeast layer and a thicker, but more open, hyphal layer The hypha- mutant produced only the basal layer, whereas the yeast- mutant formed a thicker, hyphal biofilm equivalent to the outer zone of the wild-type structures Biofilms of the yeast- mutant were more easily detached from the catheter surface than the others, suggesting that the basal yeast layer has an important role in anchoring the biofilm to the surface Biofilms formed on cylindrical cellulose filters were quite different in appearance The hypha- mutant and both wild types produced exclusively yeast-form biofilms whereas the yeast- mutant generated a dense hyphal mat on the top of the filter All these biofilms, irrespective of morphological form, were resistant to the antifungal agent, amphotericin B Overall, these results indicate that the structure of a C albicans biofilm depends on the nature of the contact surface, but that some surfaces produce biofilms with a layered architecture resembling to that described for bacterial systems
298 citations