1. Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Taian, 271018, China
2. College of Veterinary Medicine, Shandong Agricultural University, Taian, 271018, China
3. State Key Laboratory of Pathogen and Biosecurity, Beijing, 100071, China
4. Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China