COMPARISON BETWEEN RIBOTYPING AND RESTRICTION ENZYME ANALYSIS FOR INTER- AND INTRASPECIES DISCRIMINATION OF BORDETELLA AVIUM AND BORDETELLA HINZII

Authors: Register, Karen; Sacco, Randy; Nordholm, Gwen

Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2003
Publication Date: 4/20/2003
Citation: REGISTER, K.B., SACCO, R.E., NORDHOLM, G.E. COMPARISON OF RIBOTYPING AND RESTRICTION ENZYME ANALYSIS FOR INTER- AND INTRASPECIES DISCRIMINATION OF BORDETELLA AVIUM AND BORDETELLA HINZII. JOURNAL OF CLINICAL MICROBIOLOGY. 2003. v. 41(4). p. 1512-1519.

Interpretive Summary: Bordetella avium is a bacterium that infects poultry and causes upper respiratory tract disease responsible for substantial economic losses to the turkey industry. There is presently no method useful for distinguishing one isolate from another, which hampers the investigation of outbreaks and prevents a complete understanding of how the organism is transmitted between and within flocks. A related, newly recognized bacterium, Bordetella hinzii, has also been acquired from the respiratory tracts of diseased poultry but is not believed to actually cause disease in birds. Additionally, several disease-causing human isolates have recently been reported, one of which caused the death of a patient. Therefore, accurate identification of B. hinzii is of importance for both veterinary and human diagnostic laboratories. However, there is no reliable test to distinguish B. avium from B. hinzii. In this study, we demonstrated that two different methods based on DNA sequence, ribotyping, and restriction endonuclease analysis are useful for identification of B. avium and B. hinzii and for distinguishing different isolates of the same organism from one another. These techniques revealed that numerous isolates of B. hinzii, some of which were shown to cause disease in poults, were previously misidentified. Therefore, the assumption that B. hinzii is not able to cause disease in poultry may be erroneous and should be re-examined.

Technical Abstract: Bordetella avium is an avian respiratory disease pathogen responsible for substantial economic losses to the turkey industry. The inability to distinguish isolates has hampered outbreak investigations and prevents a complete understanding of transmission mechanisms. Isolates of Bordetella hinzii, often referred to as B. avium-like or as Alcaligenes faecalis type II prior to 1995, have also been acquired from the respiratory tracts of diseased poultry but are not believed to be pathogenic for birds. Therefore, differentiating between B. avium and B. hinzii is of importance for veterinary diagnostic laboratories. It was recently reported that both PvuII ribotyping and Hinf I/DdeI restriction endonuclease analysis (REA) show promise for distinguishing isolates of B. avium and B. hinzii. Here we compared the ability of these techniques to discern inter- and intraspecies differences. While both approaches distinguished numerous types within a species, only REA was sufficiently discriminatory for routine use as an epidemiologic tool. Both techniques clearly distinguish between B. avium and B. hinzii, although the results of ribotyping are more easily interpreted. Ribotyping and REA identified numerous, previously unrecognized, B. hinzii strains from a collection of bordetellae isolates, including one acquired from a rabbit. This is the first report of B. hinzii isolation from a non-human mammalian species. At least some of the newly recognized B. hinzii isolates have been previously reported to cause disease in poults, suggesting that the pathogenicity of this agent for poultry should be more rigorously examined.