1. United Graduate School of Veterinary Sciences, Yamaguchi University, Yamaguchi 753–8515, Japan
2. Department of Veterinary Public Health, Faculty of Agriculture, Tottori University, 4–101 Koyama-Minami, Tottori 680–8553, Japan
3. Avian Zoonoses Research Center, Faculty of Agriculture, Tottori University, 4–101 Koyama-Minami, Tottori 680–8553, Japan