1. National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
2. Qinghai Academy of Animal and Veterinary Science, Weier Road, Xining, Qinghai 810003, China
3. Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Ziyue Road, Minhang District, Shanghai 200241, China