1. College of Animal Science and Technology, Guangxi University, Nanning 530005, China
2. China Animal Disease Control Center, Beijing 102618, China
3. Institute of Human Virology, Department of Pathogen Biology and Biosecurity, and Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
4. State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China
5. College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, China