The Bvg virulence control system regulates biofilm formation in Bordetella bronchiseptica.
Bordetella species utilize the BvgAS (Bordetella virulence gene) two-component signal transduction system to sense the environment and regulate gene expression among at least three phases: a virulent Bvg+ phase, a nonvirulent Bvg- phase, and an intermediate Bvgi phase. Genes expressed in the Bvg+ phase encode known virulence factors, including adhesins such as filamentous hemagglutinin (FHA) and fimbriae, as well as toxins such as the bifunctional adenylate cyclase/hemolysin (ACY). Previous studies showed that in the Bvgi phase, FHA and fimbriae continue to be expressed, but ACY expression is significantly downregulated. In this report, we determine that Bordetella bronchiseptica can form biofilms in vitro and that the generation of biofilm is maximal in the Bvgi phase. We show that FHA is required for maximal biofilm formation and that fimbriae may also contribute to this phenotype. However, expression of ACY inhibits biofilm formation, most likely via interactions with FHA. Therefore, the coordinated regulation of adhesins and ACY expression leads to maximal biofilm formation in the Bvgi phase in B. bronchiseptica.
Irie
Yasuhiko
Y
Department of Microbiology, University of Pennsylvania School of Medicine, 201C Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6084, USA.
Mattoo
Seema
S
Yuk
Ming H
MH
D000222:Adaptation, Physiological; D037361:Adenylate Cyclase Toxin / Q000235:genetics / Q000378:metabolism; D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism; D001422:Bacterial Adhesion / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D016950:Bordetella bronchiseptica / Q000166:cytology / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D006388:Hemagglutinins / Q000235:genetics / Q000378:metabolism; D009525:Niacin / Q000378:metabolism; D018085:Regulon; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014774:Virulence / Q000235:genetics*; D010566:Virulence Factors, Bordetella / Q000235:genetics / Q000378:metabolism
D037361:Adenylate Cyclase Toxin; D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; C065601:BvgA protein, Bacteria; D006388:Hemagglutinins; D014157:Transcription Factors; D010566:Virulence Factors, Bordetella; D009525:Niacin