title: Quorum sensing-dependent biofilms enhance colonization in Vibrio cholerae.
abstract: Vibrio cholerae is the causative agent of the diarrheal disease cholera. By an incompletely understood developmental process, V. cholerae forms complex surface-associated communities called biofilms. Here we show that quorum sensing-deficient mutants of V. cholerae produce thicker biofilms than those formed by wild-type bacteria. Microarray analysis of biofilm-associated bacteria shows that expression of the Vibrio polysaccharide synthesis (vps) operons is enhanced in hapR mutants. CqsA, one of two known autoinducer synthases in V. cholerae, acts through HapR to repress vps gene expression. Vibrio biofilms are more acid resistant than planktonic cells. However, quorum sensing-deficient biofilms have lower colonization capacities than those of wild-type biofilms, suggesting that quorum sensing may promote cellular exit from the biofilm once the organisms have traversed the gastric acid barrier of the stomach. These results shed light on the relationships among biofilm development, quorum sensing, infectivity, and pathogenesis in V. cholerae.
authors.affiliation: Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.forename: John J
authors.initials: JJ
authors.lastname: Mekalanos
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn / Q000382:microbiology; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000378:metabolism; D018441:Biofilms; D002771:Cholera / Q000382:microbiology / Q000503:physiopathology; D010450:Endopeptidases / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects / Q000502:physiology*; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008855:Microscopy, Electron, Scanning / Q000379:methods; D009154:Mutation; D023282:Nuclease Protection Assays; D020411:Oligonucleotide Array Sequence Analysis; D010933:Plankton / Q000382:microbiology; D012097:Repressor Proteins / Q000378:metabolism*; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism*; D014734:Vibrio cholerae / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; C064778:LuxR autoinducer binding proteins; D000217:Acyltransferases; C119535:phlorisovalerophenone synthase; D010450:Endopeptidases