云南省迪庆藏族自治州19株耐甲氧西林的金黄色葡萄球菌分子流行病学分析

Analysis on 19 MRSA molecular epidemiology in Diqing prefecture of Yunnan province

[目的]对云南省迪庆藏族自治州2012-2013年两家医院分离的金黄色葡萄球菌(MRSA)菌株进行了分子流行病学分析,以此了解该地区MRSA耐药情况。[方法]采用脉冲场凝胶电泳(Pulsed-Feld Gel Electrophoresis,PFGE)、多位点测序分析(multilocus sequence typing,MLST),药物敏感试验和毒力基因检测等方法对19株MRSA进行分析研究。[结果]所有菌株对β-内酰胺类抗生素耐药,部分菌株对喹诺酮类、大环内酯类、四环素以及磺胺类药物耐药;毒力基因检测结果表明,所有菌株均携带有溶血素基因以及不同组合的肠毒素基因;PFGE结果显示19个菌株共产生11个PFGE带型,具有非常高的分辨率水平;MLST分型结果显示,19株MRSA共产生3个ST型别,其中以ST59和ST121型菌株为主。[结论]云南省迪庆藏族自治州MRSA菌株耐药水平不容忽视,菌株的毒力基因携带情况增加了病原菌的致病能力;MRSA的流行株在迪庆藏族自治州地区均有不同程度的分布,同时PFGE对MRSA的分型水平高于MLST,同时又与MLST分型方法具有良好的相关性。

Objective We do epidemiological analysis on isolated MRSA（methicillin-resistant Staphylococcus aureus）bacteria strain in two hospitals from 2012 to 2013 in Diqing. Methods Analysis is by Pulsed-field gel electrophoresis（PFGE） and multilocus sequence typing（MLST） methods. Analyzes and studies 19 strain MRSA by drug sensitivity test and virulence genes test detection. Results The results shows all the MRSA were resistant to β-lactamase antibiotics, parts of the strains were resistant to quinolone, macrolides, tetracycline and trimethoprim/sulfamethoxazole. All the MRSA had the hemolysin genes, and different combined enterotoxin genes. 11 PFGE patterns and 3 ST types were shown for all the MRSA, ST59 and ST121 were the major types. Conclusions The antibiotics resistant problem become serious issue in Diqing prefecture, and different virulence genes increased the pathogenic abilities of the bacteria. PFGE shows the higher discriminatory power than MLST typing method for MRSA; meanwhile, the PFGE results had the well correlation with the MLST typing results in our study.