Genetic heterogeneity of Campylobacter concisus determined by pulsed field gel electrophoresis-based macrorestriction profiling.

In order to investigate the genetic diversity of Campylobacter concisus to assist molecular typing studies, the use of macrorestriction profiling was examined. A suitable protocol was developed that included the use of formaldehyde pretreatment to prevent DNA degradation, and restriction enzyme NotI for pulsed field gel electrophoresis-based genotyping. Subsequently, 53 strains of C. concisus, principally from cases of diarrhoea in children, were examined. Fifty-one distinct patterns were obtained, indicating the high discriminatory potential of the method. Patterns comprised between one and 14 restriction fragments, with type and reference strains of two well-defined genomospecies of oral and faecal origin containing six and 12 fragments respectively. Our results show that C. concisus is genetically diverse and suggest the species as currently defined to be a taxonomic continuum comprised of several genomospecies. The pulsed field gel electrophoresis typing method described here has considerable potential for molecular epidemiological studies of C. concisus and may be a useful adjunctive method for helping to resolve key taxonomic issues for this species.