1. Fukushima Prefectural Kenchu Livestock Hygiene Service Center, 2 Mansuida, Koriyama, Fukushima 963–8041, Japan
2. Iwate Prefecture Northern Regional Livestock Hygiene Service Center, 23–9–1 Yamauchi, Karumai, Iwate 028–6222, Japan
3. Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, 3–1–5 Kannondai, Tsukuba, Ibaraki 305–0856, Japan
4. Agriculture, Forestry and Fisheries Research Council Secretariat, Ministry of Agriculture, Forestry and Fisheries, 1–2–1 Kasumigaseki, Chiyoda-ku, Tokyo 100–8950, Japan
5. The United Graduate School of Veterinary Sciences, Gifu University, 1–1 Yanagido, Gifu 501–1193, Japan