Title: | Quorum-sensing control of biofilm factors in Staphylococcus epidermidis |
Author(s): | Vuong C; Gerke C; Somerville GA; Fischer ER; Otto M; |
Address: | "Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA" |
ISSN/ISBN: | 0022-1899 (Print) 0022-1899 (Linking) |
Abstract: | "Staphylococcus epidermidis is the most frequent cause of nosocomial sepsis and catheter-related infections, in which biofilm formation is considered to be the main virulence mechanism. Quorum-sensing systems have been recognized as important regulators of virulence and biofilm formation in many bacteria. There is a single quorum-sensing system in S. epidermidis encoded by the agr operon. To investigate quorum-sensing control of biofilm formation, we constructed an agr deletion mutant, assayed for the different stages of biofilm formation, and determined agr-dependent regulation of biofilm factors. The agr mutant showed increased biofilm formation, primary attachment, and expression of the autolysin AtlE, but lacked delta-toxin production. However, the level of polysaccharide intercellular adhesin expression was equivalent to the isogenic wild-type strain. In contrast to AtlE, which is known to influence primary attachment, delta-toxin appeared to exert its effect on attachment to polystyrene during later stages of biofilm formation. Importantly, addition of cross-inhibiting pheromones mimicked an agr mutation and significantly enhanced biofilm formation, which suggests that care should be used when treating S. epidermidis infections with cross-inhibiting peptides. Our data demonstrate the importance of quorum sensing in the establishment of a biofilm in this critical human pathogen" |
Keywords: | "Bacterial Adhesion Bacterial Proteins/*genetics/*metabolism Bacterial Toxins/genetics/metabolism Biofilms/*growth & development *Gene Deletion *Gene Expression Regulation, Bacterial Microscopy, Electron, Scanning N-Acetylmuramoyl-L-alanine Amidase/genetic;" |
Notes: | "MedlineVuong, Cuong Gerke, Christiane Somerville, Greg A Fischer, Elizabeth R Otto, Michael eng 2003/08/23 J Infect Dis. 2003 Sep 1; 188(5):706-18. doi: 10.1086/377239. Epub 2003 Aug 11" |