title: Identification and characterization of two Bordetella avium gene products required for hemagglutination.
abstract: Bordetella avium causes bordetellosis in birds, a disease similar to whooping cough caused by Bordetella pertussis in children. B. avium agglutinates guinea pig erythrocytes via an unknown mechanism. Loss of hemagglutination ability results in attenuation. We report the use of transposon mutagenesis to identify two genes required for hemagglutination. The genes (hagA and hagB) were adjacent and divergently oriented and had no orthologs in the genomes of other Bordetella species. Construction of in-frame, unmarked mutations in each gene allowed examination of the role of each in conferring erythrocyte agglutination, explanted tracheal cell adherence, and turkey poult tracheal colonization. In all of the in vitro and in vivo assays, the requirement for the trans-acting products of hagA and hagB (HagA and HagB) was readily shown. Western blotting, using antibodies to purified HagA and HagB, revealed proteins of the predicted sizes of HagA and HagB in an outer membrane-enriched fraction. Antiserum to HagB, but not HagA, blocked B. avium erythrocyte agglutination and explanted turkey tracheal ring binding. Bioinformatic analysis indicated the similarity of HagA and HagB to several two-component secretory apparatuses in which one product facilitates the exposition of the other. HagB has the potential to serve as a useful immunogen to protect turkeys against colonization and subsequent disease.
authors.affiliation: James Madison University, Harrisonburg, Virginia 22807, USA. templelm@CISAT.JMU.EDU
authors.forename: Louise M
authors.initials: LM
authors.lastname: Temple
authors.forename: David M
authors.initials: DM
authors.lastname: Miyamoto
authors.forename: Manju
authors.initials: M
authors.lastname: Mehta
authors.forename: Christian M
authors.initials: CM
authors.lastname: Capitini
authors.forename: Stephen
authors.initials: S
authors.lastname: Von Stetina
authors.forename: H John
authors.initials: HJ
authors.lastname: Barnes
authors.forename: Vern L
authors.initials: VL
authors.lastname: Christensen
authors.forename: John R
authors.initials: JR
authors.lastname: Horton
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Spears
authors.forename: Paul E
authors.initials: PE
authors.lastname: Orndorff
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D042482:Bordetella avium / Q000472:pathogenicity*; D002448:Cell Adhesion; D002478:Cells, Cultured; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004847:Epithelial Cells / Q000382:microbiology; D004912:Erythrocytes / Q000382:microbiology; D023061:Gene Order; D006168:Guinea Pigs; D006384:Hemagglutination; D006388:Hemagglutinins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011201:Poultry Diseases / Q000382:microbiology; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D014132:Trachea / Q000382:microbiology; D014422:Turkeys
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D006388:Hemagglutinins