Survey of pathogenicity of Rickettsia species on dogs and distribution of Rickettsia species in Hokkaido.

采用PCR和IFA对北海道的犬和犬感染的蜱进行立克次体检查。用PCR方法从1份犬血标本中检出立克次体，PCR产物序列分析表明，所获得的序列与立克次体密切相关。猫血清学调查显示，8.9%的犬血清中存在立克次体高滴度，提示北海道有大量犬暴露于立克次体。24%的犬感染蜱携带立克次体，提示犬可能将蜱携带的立克次体带到人类环境中;在松鼠感染的蚤中也检测到与犬感染立克次体密切相关的立克次体，提示蚤在立克次体传播给犬中可能起一定作用。

Dogs and ticks infected with dogs in Hokkaido were examined for Rickettsia species using PCR and IFA. The rickettsial agent was detected by PCR in one canine blood sample, and the sequence analysis of the PCR product showed that the obtained sequence was closely related to R. felis. Serological survey showed that 8.9% of dogs had high serum titer to Rickettsia species, which revealed that large number of dogs in Hokkaido was exposed to rickettsial agents. Twenty-four percent of ticks infested with dogs harbored rickettsial agents, which suggested that dogs may bring rickettsial agents in ticks to the human environment.Rickettsia species closely related to the rickettsial agent detected in dog was also detected in the flea infested with the squirrel, Sciurus vulgaris orientis, which may suggest that the flea has some role in transmission of rickettsiae to dogs.