1. Department of Biological Sciences, Okinawa Prefectural Institute of Health and Environment, Okinawa, Japan
2. Division of Pathology and Microbiology, Department of Health Science, Fukuoka Institute of Health and Environmental Sciences, Fukuoka, Japan
3. Laboratory of Food Microbiology and Food Safety, School of Veterinary Medicine, Rakuno Gakuen University, Hokkaido, Japan