Unexpected Similarities betweenBordetella aviumand Other Pathogenic Bordetellae

Abstract

Bordetella avium causes an upper respiratory tract disease (bordetellosis) in avian species. Commercially raised turkeys are particularly susceptible. Like other pathogenic members of the genus Bordetella (B. pertussis and B. bronchiseptica) that infect mammals, B. avium binds preferentially to ciliated tracheal epithelial cells and produces similar signs of disease. These similarities prompted us to study bordetellosis in turkeys as a possible nonmammalian model for whooping cough, the exclusively human childhood disease caused by B. pertussis. One impediment to accepting such a host-pathogen model as relevant to the human situation is evidence suggesting that B. avium does not express a number of the factors known to be associated with virulence in the other two Bordetella species. Nevertheless, with signature-tagged mutagenesis, four avirulent mutants that had lesions in genes orthologous to those associated with virulence in B. pertussis and B. bronchiseptica (bvgS, fhaB, fhaC, and fimC) were identified. None of the four B. avium genes had been previously identified as encoding factors associated with virulence, and three of the insertions (in fhaB, bvgS, and fimC) were in genes or gene clusters inferred as being absent or incomplete in B. avium, based upon the lack of DNA sequence similarities in hybridization studies and/or the lack of immunological cross-reactivity of the putative products. We further found that the genotypic arrangements of most of the B. avium orthologues were very similar in all three Bordetella species. In vitro tests, including hemagglutination, tracheal ring binding, and serum sensitivity, helped further define the phenotypes conferred by the mutations. Our findings strengthen the connection between the causative agents and the pathogenesis of bordetellosis in all hosts and may help explain the striking similarities of the histopathologic characteristics of this upper airway disease in avian and mammalian species.

Adenylate Cyclase Toxin (ACT) fromBordetella hinzii: Characterization and Differences from ACT ofBordetella pertussis

“…More recently, however, these same authors have found genes in B. hinzii, B. holmesii, and B. trematum that they had previously reported to be missing (24). Additionally, in B. avium, three genes (fhaB, bvgS, and fimC) that were originally thought to be absent from the genome have also been identified (76). Thus, it was not surprising that in this study we were able to identify cyaA in the B. hinzii chromosome.…”

Molecular Pathogenesis, Epidemiology, and Clinical Manifestations of Respiratory Infections Due toBordetella pertussisand OtherBordetellaSubspecies

“…B. avium is a bird pathogen causing coryza and rhinotracheitis in poultry (263,718). B. hinzii is found mainly as a commensal of the respiratory tracts of fowls but has pathogenic potential in immunocompromised humans (171,404).…”

Pertussis: Microbiology, Disease, Treatment, and Prevention

“…Although B. pertussis has been classically identified as the sole agent responsible for whooping cough, other species (i.e., B. parapertussis and B. holmesii) can also cause coughing that resembles whooping cough (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28). B. pertussis is a Gram-negative, pleomorphic aerobic coccobacillus that grows optimally on either Bordet-Gengou or Regan-Lowe agar between 35°C and 37°C and can be differentiated from other Bordetella species based on its growth and biochemical characteristics.…”