A new genomic species in Borrelia burgdorferi sensu lato isolated from Japanese ticks.

Five Borrelia strains (Ika2, HO14, Cow611C, 0612 and F63B) isolated from Ixodes ovatus ticks in Japan were analysed by DNA-DNA hybridization experiments, ribotyping, pulsed-field gel electrophoresis and protein electrophoresis. DNA relatedness set these strains in a new genomic species within the Borrelia burgdorferi complex; this species appears to be restricted to Japan and could be non-pathogenic for humans. The ribotype and pulsotype of strain Ika2 were atypical of the new genomic species.