Occurence of Bordetella bronchiseptica in domestic cats with upper respiratory tract infections

Bordetella bronchiseptica is a widespread Gram-negative pathogen occurring in different mammal species. It is known to play a role in the etiology of infectious atrophic rhinitis of swine, canine kennel cough, respiratory syndromes of cats, rabbits and guinea pigs, and sporadic human cases have also been reported. The aim of this article is to present the occurrence of infections caused by these bacteria in domestic cats with respiratory symptoms, as well as to conduct a molecular analysis of the flaA gene B. bronchiseptica for the purpose of ascertaining whether cats become infected with one or more bacteria strains. B. bronchiseptica was isolated from the respiratory system of 16 out of 35 domestic cats with symptoms of respiratory tract infections. Polymorphism analysis of polymerase chain reaction products of B. bronchiseptica flaA was performed to reveal the possible differences in nucleotide sequences of the flagellin gene. The phylogenetic analysis of nucleotide sequences obtained during PCR indicated that the isolates of bacteria from our own studies are characterised by 100% homology of the analysed fragment of the flaA gene, which suggests maintenance of a single genotype of these microorganisms in the cat population. Moreover, the bacteria revealed full homology with reference strain B. bronchiseptica ATCC 4617, and 99.4% homology with strain B. parapertussis ATCC 15311. This indicates that the PCR optimised for the Bordetella spp. flaA gene, combined with sequencing of amplicons obtained in PCR, is an effective diagnostic method allowing differentiation of Bordetella spp. type microorganisms.