1. National Institute of Cholera and Enteric Diseases, P-33, CIT Road, Beliaghata, Kolkata – 700 010, India 2Jadavpur University, Jadavpur, Kolkata – 700 032, India 3Jissen Women's University, 4-1-1, Osakane Hinocity, Tokyo 191-8510, Japan 4International Centre for Diarrhoeal Diseases Research, Bangladesh, Mohakhali, Dhaka – 1212, Bangladesh