Dissemination of Methicillin-Resistant Staphylococcus aureus Sequence Type 764 Isolates with Mupirocin Resistance in China

• DOI: 10.1128/spectrum.03794-22
• Publication Date: 2023-01-09T14:43:02Z
• Authors: Yinjuan Guo; Linling Xu; Bingjie Wang; Lulin Rao; Yanlei Xu; Xinyi Wang; Huilin Zhao; Jingyi Yu; Ying Zhou; Fangyou Yu
• Keywords: Mupirocin; Sequence (biology)

Mupirocin, a topical antimicrobial agent, is an important component in the eradication of methicillin-resistant Staphylococcus aureus (MRSA) colonization. The molecular characteristics 46 mupirocin-resistant MRSA (MR-MRSA) clinical isolates were analyzed by multilocus sequence typing (MLST), staphylococcal cassette chromosome mec element (SCCmec) typing, spa and analysis virulence genes. All 26 with low-level mupirocin resistance possessed V588F mutation ileS. Among 20 high-level to mupirocin, all carried mupA; 2 also ileS, 1 V631F ileS (isoleucyl-tRNA synthetase). majority MR-MRSA resistant erythromycin, clindamycin, tetracycline, ciprofloxacin, gentamicin, but rates rifampin fusidic acid 8.7% 6.5%, respectively. Eight types (STs) found among isolates, which ST764 was most prevalent (76.1%). frequent type identified t1084 (52.2%). SCCmec frequently II (80.4%). common clone ST764-MRSA-SCCmec II-t1084 (23 isolates), while II-t002 (9 isolates) isolates. Additionally, toxin genes except seb gene not clonal complex 5 (CC5) immune evasion cluster (IEC)-associated (chp, sak, scn) present absent ST5, sec, sel1, tsst-1, hlb ST5 ST764. In conclusion, spread CC5 clones, especially novel responsible for increase resistance. These findings indicated that emergence involves therapeutic challenge treating serious infections. IMPORTANCE antibiotic commonly used nasal decolonization methicillin-sensitive hospital settings nursing homes, introduced as highly effective against MRSA. Mupirocin acts competitively binding isoleucyl-tRNA synthetase, thereby disrupting protein synthesis. This drug shows bacteriostatic bactericidal activity at low high concentrations, However, use, during treatment has been reported. previous study, proportion strains Canadian increased from 1.6% first years surveillance (1995 1999) 7.0% (2000 2004).