深圳市金黄色葡萄球菌耐药性分析及分子分型

目的 了解深圳市金黄色葡萄球菌的耐药性特点及分子分型特征。方法 收集2012年来自深圳市7所医院的428株金黄色葡萄球菌，以琼脂稀释法测定其对12种抗菌药物的最低抑菌浓度（MIC），采用聚合酶链式反应（PCR）检测杀白细胞毒素（PVL），并对携带PVL基因的菌株进行多位点基因序列分型（MLST）。结果 428株金黄色葡萄球菌中耐甲氧西林金黄色葡萄球菌（MRSA）116株（26.2%），甲氧西林敏感金黄色葡萄球菌（MSSA）312株（73.8%）。12种抗菌药物中，该菌对青霉素和红霉素的耐药率最高，分别为88.8%和44.2%；未发现替考拉宁、利奈唑胺和万古霉素的耐药株。MRSA对青霉素和环丙沙星的耐药率显著高于MSSA。428株金黄色葡萄球菌中，60株（14.02%）携带PVL基因。MLST分型结果显示共有14种已知序列型和4种新的序列型，其中ST59和ST338最多，分别为16株和12株。结论 深圳地区金黄色葡萄球菌MRSA检出率以及对多种抗菌药物的耐药率均低于全国平均水平，PVL基因阳性率处于中等水平；存在多种ST分型，以ST59和ST338多见，具有遗传多样性和独特的遗传背景。

Antibiotic resistances and molecular typing of Staphylococcus aureus in Shenzhen

Objective To learn the antibiotic resistance and molecular typing of Staphylococcus aureus in Shenzhen. Methods 428 strains of Staphylococcus aureus were collected from seven hospitals in Shenzhen in 2012. Their minimum inhibitory concentrations (MICs) against 12 antibiotics were determined with agar dilution method. Panton-Valentine leucocidin(PVL) was detected by using polymerase chain reaction(PCR). Strains carrying PVL gene were detected with multilocus sequence typing(MLST). Results 116(26.2%) strains of MRSA and 312(73.8%) strains of MSSA were detected. The resistance rates to Penicillin and Erythromycin were the highest (88.8% and 44.2% respectively). No isolates resistant to Teicoplanin, Linezolid and Vancomycin were found. The drug resistance rates of MRSA to Penicillin and Ciprofloxacin were significantly higher than those of MSSA. 60 strains carried PVL gene, among which 14 kinds of known sequences and 4 kinds of new sequence types were found by MLST, with ST59 and ST338 being the most common types (16 and 12 strains respectively). Conclusion In Shenzhen, the MRSA detection rate and antibiotic resistance rate of Staphylococcus aureus are below the national average level, and the positive rate of PVL gene is at medium level. There are many kinds of sequences, among which ST59 and ST338 are the most common types, suggesting a genetic diversity and unique genetic background.