头孢西丁和拉氧头孢纸片扩散法检测耐甲氧西林凝固酶阴性葡萄球菌的方法比较

Comparison of cefoxitin and moxalactam disc diffusion methods for detection of methicillin resistance in coagulase-negative staphylococci

目的:采用头孢西丁和拉氧头孢30μg纸片扩散法检测耐甲氧西林凝固酶阴性葡萄球菌(MRCoNS),并进行比较分析。方法:分别采用纸片扩散法检测头孢西丁(cefoxitin,FOX)和拉氧头孢(moxalactam,MOX)对临床分离的214株凝固酶阴性葡萄球菌(CoNS)的敏感性,并将检测结果与PCR法和青霉素结合蛋白(PBP2a)乳胶凝集试验检测结果进行比较。结果:经PCR法和PBP2a乳胶凝集试验检测,214株CoNS检出MRCoNS186株。头孢西丁、拉氧头孢纸片扩散法检测MRCoNS的敏感性和特异性分别为100.0%、100.0%和87.1%、90.3%。两者总符合率为99.4%。结论:拉氧头孢纸片扩散法用于批量检测MRCoNS与头孢西丁纸片扩散法一样有着很高的敏感性和相似的特异性,两者之间有很好的符合率。

Objective：To compare cefoxitin and moxalactam 30 μg disc diffusion（DD）methods in detecting methicillin-resistance in coagulase-negative staphylococci（MRCoNS）.Methods：Two hundred and fourteen strains of clinically isolated coagulase-negative staphylococci（CoNS）were tested by cefoxiti and moxalactam 30 μg DD methods,and the result was compared with that by penicillin-binding protein（PBP2a）and polymerase chain reaction（PCR）detection.Results：One hundred and eighty-six strains of MRCoNS were identificated by PCR and PBP2a）latex agglutination test.The sensitivity/specificity of cefoxitin and moxalactam were 100.0%/100.0% and 90.3%/87.1%,respectively.The results of two tests were consistent in 99.4% of the isolates.Conclusions：Moxalactam 30 μg DD method has the same sensitivity and similar specificity with cefoxitin DD method in detecting CoNS.Two DD methods show a similar intrinsic performance in detecting methicillin resistance in CoNS.