1. Division of Microbiology, National Institute of Cholera and Enteric Diseases, P-33 CIT Rd., Scheme XM, P.O. Box 177, Beliaghata, Kolkata, India
2. Department of Microbiology, Regeneration and Advanced Medical Science, Graduate School of Medicine, Gifu University, Gifu, Japan
3. International Center for Diarrhoeal Diseases and Research, Bangladesh, Dhaka, Bangladesh
4. Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan