1. Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, P. R. China
2. Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, P. R. China
3. Institute of Comparative Medicine, Yangzhou University, Yangzhou, P. R. China