Patterns of virulence gene expression differ between biofilm and tissue communities of Streptococcus pyogenes.
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.
Cho
Kyu Hong
KH
Department of Molecular Microbiology, Washington University School of Medicine, Box 8230, St Louis, MO 63110-1093, USA.
Caparon
Michael G
MG
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
D001426:Bacterial Proteins