1. Laboratory of Global Infectious Diseases Control Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
2. Inuyama Animal General Medical Center, 29 Oomishita, Haguro, Inuyama 484-0894, Japan
3. Kaltech Corporation, Hirotake Bldg. 3-3-7 Bakuromachi, Chuo-ku, Osaka 541-0059, Japan
4. Laboratory of Global Animal Resource Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan