1. Laboratory of Veterinary Public Health, Department of Veterinary Medicine, College of Bioresource Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
2. Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Harumicho 3-8-1, Fuchu, Tokyo 183-8538, Japan
3. Senior Fellow Laboratory, University of Fukui, Fukui 910-1193, Japan
4. Mahara Institute of Medical Acarology, Tokushima 779-1510, Japan
5. Department of Bacteriology-I, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku, Tokyo 162-8640, Japan