Genotypic Characterization of Bordetella bronchiseptica Strains Isolated from Stray and Pet Dogs

Bordetella bronchiseptica (B. bronchiseptica) is the most important pathogen associated with kennel cough in dogs. The presence of B. bronchiseptica in pet dogs and shelter dogs with clinical respiratory disease was investigated in present study. The genetic relatedness among the strains was determined to evaluate the role of stray dogs in spread of B. bronchiseptica to pet dogs by detection of virulence genes such as filamentous hemagglutinin (fha), pertactin (prn) and dermonecrotic toxin (dnt). We also performed the random amplified polymorphic DNA (RAPD) assay. A total of 96 B. bronchiseptica were isolated from stray and pet dogs. The fha, prn and dnt virulence genes were detected in 86, 83.3 and 61.4% strains, respectively by polymerase chain reaction (PCR) techniques. The most common genotype from stray and pet dogs was fha+prn+dnt+ as detected in 37.5% and 11.4% of all the strains, respectively. The RAPD assay showed that 3 different patterns were obtained from 96 B. bronchiseptica strains. Sixty one (63.5%) of them were clustered in one main group and then further placed in another 2 sub-groups by RAPD assay. Genetic association was seen between the B. bronchiseptica strains from stray and pet dogs. In conclusion, this study revealed that B. bronchiseptica is present at a higher rate in stray dogs than pet dogs. Stray dogs might have a significant role in the transmission of B. bronchiseptica to pet dogs.