1. Department of Clinical Microbiology and Immunology; School of Allied Health Sciences, Tokyo Medical and Dental University; Bunkyo-ku Tokyo 113-8519 Japan
2. Human Gene Sciences Center; Tokyo Medical and Dental University; Bunkyo-ku Tokyo 113-8519 Japan
3. Department of Microbiology; The Institute of Public Health; Minato-ku Tokyo 108-0071 Japan
4. Department of Bacteriology; National Institute of Infectious Diseases; Shinjuku-ku Tokyo 162-8640 Japan