1 College of Engineering, Huazhong Agricultural University, Wuhan 430070, P. R. China
2 College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, P. R. China
3 State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P. R. China
4 Bio-Medical Center, Huazhong Agricultural University, Wuhan 430070, P. R. China
5 Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, P. R. China