1. 1Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
2. 2Department of Microbiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
3. 3Base Hospital, Panadura, Sri Lanka
4. 4Department of Medicine, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
5. 5Veterinary Research Institute, Gannoruwa Road, Peradeniya, Sri Lanka
6. 6Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan