Using Core-genome Multilocus Sequence Typing to Monitor the Changing Epidemiology of Methicillin-resistant Staphylococcus aureus in a Teaching Hospital
Using Core-genome Multilocus Sequence Typing to Monitor the Changing Epidemiology of Methicillin-resistant Staphylococcus aureus in a Teaching Hospital
复制标题
使用核心基因组多位点序列分型监测教学医院耐甲氧西林金黄色葡萄球菌的流行病学变化
DOI：
10.1093/cid/ciy644
复制
发表时间：
2018-12-01
影响因子：
11.8
通讯作者：
Yu, Yunsong
中科院分区：
文献类型：
--
作者：
Chen, Yan;Sun, Lu;Yu, Yunsong
背景资料。目的了解某教学医院耐甲氧西林金黄色葡萄球菌(MRSA)的流行情况。我们对2013至2015年邵逸夫爵士医院(SRRSH)发现的MRSA分离株进行了全基因组测序和系统发育分析。对分离的MRSA进行药敏试验、耐药决定簇筛选、毒力测定和临床资料分析。在研究期间，共发现292例MRSA感染。其中，序列类型(ST)5(51.4%，292例，150例)和ST59(23.3%，292例，68例)。ST5耐甲氧西林金黄色葡萄球菌比例从2013年的68.3%下降到2015年的32.1%，ST59耐甲氧西林金黄色葡萄球菌比例从8.9%上升到41.0%。核心基因组系统发育分析显示，ST59 MRSA分离株在卫生保健首发和社区首发两组中均表现出比ST5 MRSA分离株更广泛的基因多样性。最小生成树显示ST5 MRSA聚集性在SRRSH传播，而ST59 MRSA感染大多是散发性的。93例皮肤软组织感染中，ST59株MRSA占45.2%，对左氧氟沙星和环丙沙星的耐药率分别为11.8%和19.1%，均低于ST239和ST5株。在皮肤感染模型和溶血试验中，ST59起病的MRSA显示出增强的毒力。值得注意的是，这些分离株的毒力水平与典型的社区相关MRSA株相似。具有高毒力潜力的ST59 MRSA菌株已取代ST5 MRSA成为SRRSH的优势菌株，并引起医院感染。全基因组测序是监测医院耐甲氧西林金黄色葡萄球菌流行病学变化的有力工具。
Background. This study was performed to elucidate the changing epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in a Chinese teaching hospital.Methods. We performed whole-genome sequencing and phylogenetic analysis on MRSA isolates recovered at Sir Run Run Shaw Hospital (SRRSH) from 2013 to 2015. MRSA isolates underwent susceptibility testing, resistance determinant screening, virulence assays and clinical data analysis.Results. A total of 292 MRSA infections were identified during the study period. Of these, most belonged to sequence type (ST) 5 (51.4%; 150 of 292) and ST59 (23.3%; 68 of 292). The proportion of ST5 MRSA decreased from 68.3% in 2013 to 32.1% in 2015, and the proportion of ST59 MRSA increased from 8.9% to 41.0%. Core-genome phylogenetic analysis revealed that ST59 MRSA isolates exhibited wider genotypic diversity than ST5 MRSA isolates in both healthcare-onset and community-onset groups. Minimum spanning trees showed that a cluster of ST5 MRSA was circulating at SRRSH, whereas the ST59 MRSA infections were mostly sporadic. ST59 MRSA caused 45.2% of the 93 skin and soft-tissue infection cases and displayed lower levofloxacin (11.8%) and ciprofloxacin (19.1%) resistance rates than the ST239 and ST5 MRSA isolates. ST59 healthcare-onset MRSA displayed enhanced virulence in the skin infection model and hemolysis assays. Notably, these isolates had virulence levels similar to those of classic community-associated MRSA strains.Conclusions. ST59 MRSA strains with high virulence potential have been replacing ST5 MRSA in predominance in SRRSH and causing nosocomial infections. Whole-genome sequencing is a powerful tool to monitor changes in the epidemiology of MRSA in hospitals.