1. Division of Gastroenterology, Union hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
2. Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
3. Department of Nosocomial Infection Management, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China