title: The bvg-repressed gene brtA, encoding biofilm-associated surface adhesin, is expressed during host infection by Bordetella bronchiseptica.
abstract: Bordetella species display phase modulation between Bvg(+) and Bvg(-) phases. Because expression of known virulence factors is up-regulated in the Bvg(+) phase, bacteria in this phase are considered competent for infection. However, the Bvg(-) phase is of negligible importance for infection. No studies have shown that bacterial factors specific to the Bvg(-) phase (bvg-repressed factors) are expressed in the course of Bordetella infection. In the present study, the gene brtA (Bordetella RTX-family Adhesin), which is a typical bvg-repressed gene but is expressed in B. bronchiseptica infecting hosts, was characterized. BrtA is composed of repeated pairs of the VCBS unit and dystroglycan-type cadherin-like unit, the von Willebrand Factor A domain, RTX motif and type I secretion target signal. It is herein demonstrated that BrtA is secreted by the type I secretion system and is essential for Ca(2+) -dependent bacteria-to-substrate adherence, followed by biofilm formation. Although the contribution of BrtA to bacterial colonization of the rat trachea currently remains unclear, this is the first study to present concrete evidence for the expression of a bvg-repressed gene during infection, which may provide a novel aspect for analyses of Bordetella pathogenesis.
authors.affiliation: Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Nishikawa
authors.affiliation: Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Naoaki
authors.initials: N
authors.lastname: Shinzawa
authors.affiliation: Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ishigaki
authors.affiliation: Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Abe
authors.affiliation: Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Horiguchi
mesh_terms: D018829:Adhesins, Bacterial / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018441:Biofilms; D001885:Bordetella Infections / Q000382:microbiology* / Q000473:pathology; D016950:Bordetella bronchiseptica / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D051381:Rats; D017208:Rats, Wistar; D014132:Trachea / Q000382:microbiology / Q000473:pathology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015533:Transcriptional Activation; D015854:Up-Regulation; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; C065601:BvgA protein, Bacteria; D014157:Transcription Factors; D037521:Virulence Factors
keywords: Bordetella bronchiseptica; BvgAS; biofilm; surface adhesion