1. Department of Veterinary Microbiology, College of Veterinary Medicine, BK21 Plus Program for Veterinary Science and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Korea.
2. Animal and Plant Quarantine Agency, Gimcheon 39660, Korea.
3. Department of Animal Science and Technology, College of Biotechnology and Natural Resource, Chung-Ang University, Anseong 06974, Korea.