Molecular identification and characterization of piroplasm species in Hokkaido sika deer (Cervus nippon yesoensis), Japan.

Babesia and Theileria species are tick-borne protozoan parasites that have a veterinary and zoonotic importance. In order to investigate the prevalence and genetic diversity of these parasites, a total of 269 sika deer blood DNA samples collected from Hokkaido, Japan, were examined for Babesia and Theileria species by touch-down PCR targeting the 18S rRNA gene. Reverse line blot (RLB) hybridization was then used to detect 12 piroplasm species. The results revealed that 95.5% (257/269), 94.1% (253/269), 14.1% (38/269), 87.7% (236/269) and 11.5% (31/269) of the examined PCR products hybridized with the probes which were designed to detect all Babesia and Theileria spp., all Theileria spp., all Babesia spp., Theileria sp. Thrivae and Babesia divergens-like, respectively. The 18S rRNA gene partial sequences were divided into Theileria sp. Thrivae, T. capreoli, B. divergens-like and an undescribed Babesia species. This study showed the first detection of the undescribed Babesia sp. from Japan. Therefore, more studies are required to understand the ecology of the newly detected tick-borne pathogens in Hokkaido.