Abstract:Objective To understand the molecular characteristics and main epidemic clone types of methicillin-resistant Staphylococcus aureus (MRSA) in different regions of Jiangxi Province, explore the possible competitive advantages of epidemic clone, provide information for the subsequent study on mechanism. Methods Clinical isolates of MRSA from 11 hospitals in 11 cities of Jiangxi Province between January 2017 and December 2018 were collec-ted, MRSA strains identified by mecA+femB double polymerase chain reaction (PCR) were included in study, molecular typing was performed by spa, SCCmec, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), virulence genes of Panton-Valentine leukocidin (PVL) were detected by PCR method. Results The main types of spa were t437 (74 strains, 31.22%) and t030 (32 strains, 13.50%); there were significant differences in spa types among different regions, except for t030 in Nanchang region, t437 was the dominant type in other regions. SSCCmec IVa was the dominant type (66.67%), SCCmec Ⅲ accounted for 15.19%; except for SCCmec Ⅲ in Nanchang (59.38%), SCCmec IVa was the dominant type in other regions. The dominant clone types detected by PFGE and MLST were ST239, ST59, ST1 and ST338; and the dominant clone groups were CC239, CC59 and CC1. A total of 32 strains (13.19%) of PVL-positive bacteria were detected, the highest detection rate of PVL was found in Yingtan region (29.63%, 8/27), followed by Jingdezhen region (26.32%, 5/19). Conclusion ST59-MRSA-IVa-t437 is the predominant epidemic clone type in Jiangxi, and there is a certain degree of clonal dissemination among different regions. ST239-MRSA-Ⅲ-t30 is the secondary dominant epidemic clone type, which is mainly found in Nanchang and sporadic in other regions. The main type of PVL-positive strains in Jiangxi is ST59-MRSA-t437-IVa.