Microbiological and clinical aspects of respiratory infections associated with Bordetella bronchiseptica

Bordetella bronchiseptica is a well-known veterinary pathogen, but its implication in human disease is probably not fully recognized. The purpose of this study was to determine the clinical significance of 36 B. bronchiseptica isolates from respiratory samples of 22 patients. Therefore, we describe microbiological characteristics, including phenotypic and genotypic identification as well as antimicrobial susceptibilities of the isolates. Clonal relatedness was evaluated using pulsed-field gel electrophoresis (PFGE). Most of the patients had some underlying immunosuppressive condition. Eighteen out of 22 (82%) patients had respiratory symptoms, and the death of 2 patients was associated with respiratory infection.All strains were correctly identified at species level by the simultaneous use of phenotypic methods and were confirmed by specific amplification of the upstream region of the fla gene. Tigecycline, minocycline, doxycycline, colistin, and meropenem were the most active agents tested. PFGE analysis revealed that repeated infections involving each patient had been caused by the same strain.