a study on the genetic analysis of clinical isolates and vaccine strains of bordetella pertussis by pulsed-field gel electrophoresis (pfge)

considering the circulation of bordetella pertussis clinical strains among populations with high vaccination coverage, it is necessary to have a proper understanding of this bacterium causing whooping cough. various techniques, which are available for studying b. pertussis, can facilitate a proper comparison between different populations. we genotypically analyzed a collection of two vaccine strains used for the production of killed pertussis vaccine during 2000-2014 at razi vaccine and serum research institute, karaj, iran. ten clinical and two reference (tohama 1 and 18323) strains were used by means of pulsed-field gel electrophoresis (pfge). the genetic profiles of the vaccine master and working seeds showed no significant changes in the frequency of fingerprint types in the vaccine strains; also, the homogeneity of the profiles was demonstrated. however, the clinical isolates showed heterogeneity in the genetic profiles. in addition, serotyping was performed with monoclonal antisera to agglutinogens 2 and 3. analysis of the fimbriae showed that all ten clinical strains expressed fim3.