1. The United Graduate School of Veterinary Sciences, Gifu University, 1–1 Yanagido, Gifu, Gifu 501-1193, Japan
2. Laboratory of Zoonotic Diseases, Faculty of Applied Biological Sciences, Gifu University, 1–1 Yanagido, Gifu 501-1193, Japan
3. Fukui Prefectural Livestock Hygiene Service Center, 69–10–1 Obatake, Fukui, Fukui 918-8226, Japan
4. Dairy Hygiene Research Division, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo, Hokkaido 062-0045, Japan