1. Department of Microbiology, BGC Trust Medical College, Chandanaish, Chittagong, Bangladesh
2. Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
3. Division of Microbiology, Nihon University School of Medicine, 30-1 Oyaguchi-Kamicho, Itabashi-ku, Tokyo 173-8610, Japan
4. Infectious Diseases Surveillance Center, National Institute of Infectious Diseases, Tokyo 162-8640, Japan