1. Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550, Japan
2. The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu 501-1193, Japan
3. Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori 034-8628, Japan
4. Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki, Aomori 036-8560, Japan
5. Department of Bacteriology, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima-shi, Hiroshima 734-8551, Japan