1. Laboratory of Veterinary Public Health, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa-shi, Kanagawa 252-0880, Japan
2. Division of Bacteriology, Chiba Prefectural Institute of Public Health, 666-2 Nitona-cho, Chuo-ku, Chiba-shi, Chiba 260-8715, Japan
3. Department of Animal and Grassland Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadainishi, Miyazaki-shi, Miyazaki 889-2192, Japan
4. Department of Microbiology, Kanagawa Prefectural Institute of Public Health, 1-3-1 Shimomachiya, Chigasaki-shi, Kanagawa 253-0087, Japan
5. Department of Planning and Information, Kanagawa Prefectural Institute of Public Health, 1-3-1 Shimomachiya, Chigasaki-shi, Kanagawa 253-0087, Japan
6. Department of Bacteriology, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan
7. Division of Microbiology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan