1. Gunma Livestock Health Laboratory, 2425-3 Kogure, Fujimimachi, Maebashi, Gunma 371-0103, Japan
2. Gunma Prefectural Seibu Livestock Hygiene Service Center, 233 Shimokotori, Takasaki, Gunma 370-0074, Japan
3. Tochigi Prefectural Kenou Livestock Hygiene Service Center, 6-8 Hiraide-kogyodanchi, Utsunomiya, Tochigi 321-0905, Japan
4. Division of Bacterial and Parasitic Disease, National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan
5. Division of Pathology and Pathophysiology, National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan
6. Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka 598-8531, Japan