title: Patterns of virulence gene expression differ between biofilm and tissue communities of Streptococcus pyogenes.
abstract: The ability of Streptococcus pyogenes to form biofilm-like bacterial communities during infection of soft tissue has suggested that the capacity to produce biofilm may be important for pathogenesis. To examine this relationship, a panel of mutants was evaluated for their ability to form biofilm on abiotic surfaces in several assays. Several established virulence factors were crucial for biofilm formation, including the M protein, required for initial cell-surface interactions, and the hyaluronic acid capsule, required for subsequent maturation into a three-dimensional structure. Mutants lacking the transcription regulators Mga and CovR (CsrR) also failed to form biofilm. Comparison of transcriptional profiles revealed differential regulation of approximately 25% of the genome upon adaptation to biofilm. During infection of zebrafish, several virulence factors (notably cysteine protease and streptokinase) were regulated in a biofilm-like manner. However, the overall profile of virulence factor expression indicated that tissue communities have a pattern of gene expression different from biofilm. Taken together, these data show that while biofilm and tissue communities have many characteristics in common, that biofilm reproduces only a subset of the myriad cues used by tissue communities for regulation of virulence.
authors.affiliation: Department of Molecular Microbiology, Washington University School of Medicine, Box 8230, St Louis, MO 63110-1093, USA.
authors.forename: Kyu Hong
authors.initials: KH
authors.lastname: Cho
authors.forename: Michael G
authors.initials: MG
authors.lastname: Caparon
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D004195:Disease Models, Animal; D017753:Ecosystem; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D018461:Soft Tissue Infections / Q000382:microbiology / Q000503:physiopathology*; D013290:Streptococcal Infections / Q000382:microbiology / Q000503:physiopathology*; D013297:Streptococcus pyogenes / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*; D014158:Transcription, Genetic; D014774:Virulence; D015027:Zebrafish
chemical_list: D001426:Bacterial Proteins