1. School of Public Health, Xinxiang Medical University, Xinxiang 453003, P.R. China
2. School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang 453003, P.R. China
3. Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, P.R. China
4. Gushi County Center for Animal Disease Control and Prevention, Xinyang 465200, P.R. China
5. Mingde College of Xinxiang Medical University, Xinxiang 453003, P.R. China
6. School of Biological Engineering, Xinxiang University, Xinxiang 453003, P.R. China