Polymorphism in the Pertussis Toxin Promoter Region Affecting the DNA-Based Diagnosis of BordetellaInfection

ABSTRACTThe pertussis toxin (PT) promoter region is a frequently used target for DNA-based diagnosis of pertussis and parapertussis infections. The reported polymorphism in this region has also allowed discrimination of species in mixtures with severalBordetellaspecies by their specific PCR amplicon restriction patterns. In the present study, we investigated the degree of polymorphism in order to confirm the reliability of the assay. Five different sequence types of the amplified 239- or 249-bp region were found among the 33 Bordetella pertussis, B. parapertussis, and B. bronchisepticaAmerican Type Culture Collection reference strains and patient isolates analyzed. According to the sequences that were obtained and according to the PT promoter sequences already available in the databases, restriction enzyme analysis with TaqI, BglI, andHaeII, which gave four different patterns, can be performed to reliably identify B. pertussis, B. parapertussis, and B. bronchiseptica.