Differentiation between human and ovine isolates of Bordetella parapertussis using pulsed-field gel electrophoresis.

The genetic relatedness of 18 human and 29 ovine isolates of Bordetella parapertussis was examined by macrorestriction digestion of DNA with the rarely cutting enzyme XbaI and resolution by pulsed-field gel electrophoresis. There was clear separation of human and ovine isolates and variation within host types. The human isolates were separated into three types as were the 24 Scottish ovine isolates. Species-specific bands were observed with the human isolates at 114, 134, 166, 213, 346 and 372 kb. No species-specific bands were found in the B. parapertussis ovine isolates. Isolates of B. parapertussis recovered from sheep in New Zealand gave a further two DNA banding patterns which were clearly different from the Scottish ovine and the human isolates. These results indicate that human and ovine isolates of B. parapertussis are genetically distinct and that variation exists within isolates from the same host species. Pulsed-field gel electrophoresis therefore appears to be a powerful discriminatory tool for the classification of B. parapertussis.