Evaluation of canine Bordetella bronchiseptica isolates using randomly amplified polymorphic DNA fingerprinting and ribotyping

Bordetella bronchiseptica is a respiratory tract pathogen in a variety of species. Previous studies suggest little genetic variation among canine B. bronchiseptica isolates. The degree of genetic diversity in 26 canine B. bronchiseptica strains was evaluated using randomly amplified polymorphic DNA (RAPD) fingerprinting and ribotyping. Strains evaluated include historic reference strains (N=3). vaccine strains (N=5) and clinical isolates (N=18). RAPD fingerprinting with the 10-nucleotide primer OPA-4 resulted in four distinct fingerprint patterns. RAPD fingerprinting consistently separated four previously characterized electromorphotype (EMT) 6 strains into two fingerprint types. Ribotyping, using the restriction endonuclease PvuI, resulted in six distinct ribotypes. With the exception of vaccine strains, considerable genetic diversity exists in the canine B. bronchiseptica isolates examined. These findings indicate the genetic variability within canine strains of B. bronchiseptica is greater than appreciated previously. Additionally, OPA-4 RAPD fingerprinting and PvuI ribotyping will be useful tools in epidemiologic studies of canine B. bronchiseptica isolates.