耐甲氧西林金黄色葡萄球菌产色培养基临床应用评估

Application evaluation of a chromogenic agar medium for methicillin-resistant Staphylococcus aureus

目的通过头孢西丁纸片法、耐甲氧西林金黄色葡萄球菌(MRSA)产色筛选平板法和聚合酶链反应(PCR)检测MRSA,评估MRSA产色筛选平板的敏感性和特异性。方法收集仁济医院2008年8月至9月临床分离的金黄色葡萄球菌68株,分别采用头孢西丁纸片法、MRSA产色筛选平板法和PCR检测MRSA,以PCR检测femA基因和mecA基因结果为金标准,比较MRSA产色筛选平板的敏感性和特异性。结果甲氧西林敏感金黄色葡萄球菌(MSSA)除万古霉素、替考拉宁和利奈唑胺外,对其他11种抗菌药物的敏感率明显高于MRSA。68株金黄色葡萄球菌中,头孢西丁纸片法筛选出50株MRSA,产色平板法筛选出51株MRSA,PCR检测到51株mecA基因阳性,MRSA产色筛选平板结果和mecA基因检测结果符合率为100%。结论MRSA产色筛选平板可用于临床快速检测MRSA。

Objective To evaluate the sensitivity and specificity of methicillin-resistant Staphylococcus aureus（MRSA） chromogenic agar medium by cefoxitin disk test and polymerase chain reaction（PCR） amplification of MRSA genes.Methods 68 Staphylococcus aureus strains from clinical isolates were collected from August to September 2008 in Renji hospital.The sensitivity and specificity of the MRSA chromogenic agar medium were compared with PCR standard method.MRSA were determined by cefoxitin disk test,MRSA chromogenic agar medium and PCR amplification.Results The sensitivity of 11 antibiotics from methicillin-susceptible Staphylococcus aureus（MSSA） strains was significantly higher than that from MRSA strains except the other three tested antibiotics such as vancomycin,teicoplanin and linezolid.In the 68 tested Staphylococcus aureus strains,50 strains were positive from MRSA strains by cefoxitin disk test,while 51 strains were positive for MRSA strains by chromogenic agar medium test and 51 strains were positive for mecA gene by PCR amplification.The results of MRSA chromogenic agar medium test were the same as those of PCR amplification for mecA gene.Conclusions MRSA chromogenic agar medium test can be used in fast detection of clinical MRSA strains.