1. Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
2. Department of Critical Care Medicine, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
3. Department of Microbiology, Weifang Medical University, Weifang, Shandong 261053, China