1. State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, People’s Republic of China
2. Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People’s Republic of China
3. The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, People’s Republic of China
4. College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People’s Republic of China
5. Department of Medicine, Division of Infectious Diseases, Stanford University, Stanford, CA, USA