目的 筛选异质性利奈唑胺耐药金黄色葡萄球菌(heterogeneous linezolid resistant Staphylococcus aureus,hLRSA)并对其耐药机制进行分析.方法 采用菌谱分析法筛选hLRSA,琼脂稀释法和E-test法检测MIC值,PCR方法扩增介导利奈唑胺耐药葡萄球菌耐药的cfr基因,同时扩增hLRSA 23S RNA基因并测序,并登陆GenBank,与基因库中金葡菌ATCC29213 23S RNA基因比对.结果 hLRSA检出率为1.26％(2/158);琼脂稀释法和E-test法检测异质性耐药菌株MIC结果基本一致；PCR方法没有检出cfr基因,2株hLRSA 23S RNA基因扩增后测序,与金黄色葡萄球菌23S RNA基因一致性大于99％,其中1株hLRSA 23S RNA基因序列在2474位点出现“G”→“T”点突变,可能与介导hLRSA耐药性有关.结论 利奈唑胺在体外对金黄色葡萄球菌具有较强抗菌活性,没有检出利奈唑胺中介或耐药葡萄球菌,hLRSA检出率为1.26％,耐药性可能与其23S RNA发生的点突变有关.%Objective To detect heterogeneous linezolid-resistant Staphylococcus aureus (hLRSA) , and to study its antibiotic resistance mechanism. Method Population analysis was used to detect hLRSA from clinical isolates of Staphylococci, agar dilution method and E-test were used to detect MICs, and PCR was applied to scan cfr gene from hLRSA and to sequence 23S rRNA. Result 2 strains of hLRSA (out of 158 strains) were detected(l .26%). Agar dilution method and E-test can get the same relevance ratio. No linezolid intermediate or resistant Staphylococcus aureus was detected, nor cfr gene was found from hLRSA strains by PCR. A G2474T mutation was identified in 23 S rRNA of hLRSA isolate.
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