title: The autotransporter protein from Bordetella avium, Baa1, is involved in host cell attachment.
abstract: Bordetella avium is a Gram negative upper respiratory tract pathogen of birds. B. avium infection of commercially raised turkeys is an agriculturally significant problem. Here we describe the functional analysis of the first characterized B. avium autotransporter protein, Baa1. Autotransporters comprise a large family of proteins found in all groups of Gram negative bacteria. Although not unique to pathogenic bacteria, autotransporters have been shown to perform a variety of functions implicated in virulence. To test the hypothesis that Baa1 is a B. avium virulence factor, unmarked baa1 deletion mutants (Δbaa1) were created and tested phenotypically. It was found that baa1 mutants have wild-type levels of serum sensitivity and infectivity, yet significantly lower levels of turkey tracheal cell attachment in vitro. Likewise, semi-purified recombinant His-tagged Baa1, expressed in Escherichia coli, was shown to bind specifically to turkey tracheal cells via western blot analysis. Taken together, we conclude that Baa1 acts as a host cell attachment factor and thus plays a role B. avium virulence.
authors.affiliation: Department of Integrated Science and Technology, James Madison University, Harrisonburg, VA 22807, United States. stockwsb@jmu.edu
authors.forename: S B
authors.initials: SB
authors.lastname: Stockwell
authors.forename: H
authors.initials: H
authors.lastname: Kuzmiak-Ngiam
authors.forename: N M
authors.initials: NM
authors.lastname: Beach
authors.forename: D
authors.initials: D
authors.lastname: Miyamoto
authors.forename: R
authors.initials: R
authors.lastname: Fernandez
authors.forename: L
authors.initials: L
authors.lastname: Temple
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001885:Bordetella Infections / Q000382:microbiology / Q000662:veterinary*; D042482:Bordetella avium / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D011201:Poultry Diseases / Q000382:microbiology*; D014422:Turkeys; D014774:Virulence
chemical_list: D001426:Bacterial Proteins