1. Department of Clinical Laboratory, Jinan Fourth People's Hospital, Jinan, Shandong 250031, P.R. China
2. Department of Clinical Laboratory, Jinan Infectious Disease Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
3. Bacteria Laboratory, Shandong Center for Disease Control and Prevention, Shandong 250014, P.R. China