1. Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
2. Bacteriology Section, Veterinary Research Institute, 31400 Ipoh, Perak, Malaysia.
3. Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.