Low prevalence of mupirocin resistance among Staphylococcus aureus clinical isolates from a Chinese tertiary hospital

Between September 2013 and March 2016, 26 (1.95 %) of 1333 Staphylococcus aureus clinical isolates from a Chinese hospital were found to be resistant to mupirocin, including 18 (1.35 %) with high-level mupirocin resistance and 8 (0.6 %) with low-level mupirocin resistance. Among the 18 isolates with high-level mupirocin resistance, 17 were associated with plasmid-mediated mupA. Meanwhile, the 8 isolates with low-level mupirocin resistance were shown to have a V588F mutation in ileS. A total of 14 sequence types (STs) and 18 spa types were identified. All four isolates with t062 belonged to ST965. Three ST5-MRSA-SCCmec II were linked to t311, which was not previously reported. Furthermore, ST764-MRSA-SCCmec II-t002, exclusively found in Japan before, was identified in this study. In conclusion, we observed relatively low prevalence of mupirocin resistance among S. aureus with considerable heterogeneity in East China. Newly emerging MRSA clones with high-level mupirocin resistance should be of concern.