Submitted to: American Society for Microbiology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: February 22, 2008
Publication Date: June 1, 2008
Citation: Register, K.B., Kunkle, R.A. 2008. Strain-specific virulence of Bordetella hinzii in turkeys [abstract]. American Society for Microbiology Annual Meeting. Poster No. Z-023. Technical Abstract: Bordetella hinzii is commonly acquired from the respiratory tract of diseased poultry but regarded as nonpathogenic in avian hosts. Recently, it was recognized that some previously used isolates were misidentified at the time of their acquisition as B. avium, B. avium-like or Alcaligenes faecalis type II, including a subset shown to cause disease in turkey poults. The goal of this study was to determine whether genetically and phenotypically distinct B. hinzii strains differ in their ability to colonize and cause disease in turkeys. Groups of 20 poults were infected intranasally with 108CFU of one of six strains of B. hinzii. Birds were observed twice daily for clinical signs of disease. Tracheal swabs obtained on days 7 and 14 post-infection (PI) were cultured for B. hinzii, identified by PCR and biochemical testing. On day 14 PI, all birds were euthanized and bled by cardiac puncture. Tracheal samples were collected in 10% buffered-formalin for histopathological analysis. Sera were tested by ELISA for antibody to B. hinzii. Five of six B. hinzii strains colonized the trachea of poults, although only two of the five caused clinical signs of disease. Depending on the strain, poults positive for B. hinzii ranged from 80-100% at 7 days PI and 55-100% at 14 days PI. Mild to moderate tracheal lesions consistent with bordetellosis (turkey coryza) were noted in some groups of colonized poults. Antibody responses to B. hinzii were detectable in a subset of poults from every group colonized. There was no absolute correlation between the presence of clinical signs, tracheal lesions, and/or serum antibody responses. The sixth strain of B. hinzii evaluated, unique in being the only known non-human mammalian isolate, could not be re-isolated from any poult in the group. It also failed to induce clinical signs of disease or detectable antibody responses. B. hinzii strains differ in their capacity to colonize and cause disease in turkeys. The results presented demonstrate, for the first time, that some isolates are pathogenic in turkey poults and can induce microscopic tracheal lesions consistent with turkey coryza.