Epidemiological survey of Babesia species in Japan performed with specimens from ticks collected from dogs and detection of new Babesia DNA closely related to Babesia odocoilei and Babesia divergens DNA.

Detection and analysis of Babesia species from ticks recovered from dogs in Japan were attempted by PCR and nucleotide sequence analysis based on the 18S rRNA gene, respectively. A total of 1136 ticks were examined for Babesia DNA by 18S rRNA-based PCR and nucleotide sequencing. Partial sequences of Babesia canis vogeli DNA were detected from six ticks in Aomori, Nara, Hiroshima, Oita, and Okinawa Prefectures; and Babesia gibsoni Asia-1 DNA was also detected in four ticks in Osaka, Hiroshima, Miyazaki, and Okinawa Prefectures. Unique sequences of 1678 bp were also obtained from Ixodes ovatus ticks in Akita and Fukui Prefectures. The sequences were similar to those of Babesia odocoilei (97.7%) and Babesia divergens (97.6%). This is the first report of the detection of DNA belonging to this group in Japan.