1. Department of Clinical Laboratory, Tokyo Metropolitan Health and Medical Corporation Toshima Hospital, 33-1 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
2. Department of Microbiology and Immunology, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan