江苏地区金黄色葡萄球菌耐药及分子分型研究

目的研究江苏省不同地区金葡菌的耐药性、耐药基因和分子分型的特征联系。方法收集2017年全省各市哨点医院金黄色葡萄球菌227株,采用微量肉汤稀释法测定15种抗生素最小抑菌浓度,PCR方法检测7种不同的耐药基因,并用多位点序列分型(multilocus sequence typingMLST)进行分子分型。结果本研究中金葡菌对青霉素、红霉素、头孢西丁、苯唑西林、克林霉素、左氧氟沙星、四环素、庆大霉素的耐药率较高,而对替考拉宁、利福平、复方新诺明、达托霉素、利奈唑胺以及呋喃妥因多呈敏感,耐药率均低于10%,且所有菌株均对万古霉素敏感。共计检出117株MRSA,MRSA平均耐药种数和平均耐药基因携带数高于MSSA(P<0.05)。江苏省苏北地区的菌株耐药种数要高于苏中和苏南地区(P<0.05),而苏中地区的耐药基因平均携带数高于苏南地区(P<0.05)。在227株金葡菌中发现了60个ST型,以ST59和ST398分布数量最多,并有29个新ST型。成簇菌株中,CC59的平均耐药种数和MRSA检出率均高于其他克隆群。结论江苏省内不同地区的金葡菌耐药率和耐药机制存在差异,且以CC59克隆群耐药情况最为严峻。

Antimicrobial resistance features and molecular typing of Staphylococcus aureus in Jiangsu Province,China

In order to study the characteristics of drug resistance, resistance genes and genotype of Staphylococcus aureus in different areas of Jiangsu Province, a total of 227 Staphylococcus aureus from each hospital were collected during January 2017 and December 2017. Fifteen Antimicrobial minimal inhibitory concentrations were detected by method of micro-dilution broth. Seven different resistance genes were detected by PCR. Molecular typing was performed using multilocus sequence typing (MLST). Results indicated that the 227 strains of S.aureus showed high drug resistance rate to penicillin, erythromycin, cefoxitin, oxacillin, clindamycin, levofloxacin, tetracycline and gentamycin. Though the strains were sensitive to teicoplanin, rifampin, sulfamethoxazole, daptomycin, linezolid and macrodantin, the drug resistance rates were less than 10%. The results also revealed that all isolates were sensitive to vancomycin. Of 117 strains of MRSA were found that the average drug-resistance types and the carrying number of the drug-resistance genes higher than those of MSSA (P<0.05). The strains from north of Jiangsu Province exhibited a more number of drug-resistance than midland and south, while drug-resistance genes of Midland had more quantity than the south. Sixty STs were discovered in the 227 strains of S.aureus, and twenty-nine of them were novel. ST59 and ST398 distribute the largest number in all isolates. Clone complex 59 (CC59) indicated a higher number of drug-resistance and detected rate of MRSA than any other clone complex. In conclusion, the isolates of S.aureus from different area in Jiangsu Province display differences between drug-resistance rate and drug-resistance mechanism, and the strains of CC59 had a grim situation to drug-resistance.