1. Division of Infectious Animal Disease Research, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
2. Applied Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu, Japan
3. Pathogenetic/Applied Veterinary Science, Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu, Japan