1. MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
2. Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
3. Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
4. University of Alberta, Edmonton, Alberta, Canada