1. Department of Infectious Diseases, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
2. Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, P.R. China
3. Institute of Hepatopathy, Changzhi Medical College, Changzhi, Shanxi 046011, P.R. China