头孢西丁纸片扩散法检测耐甲氧西林葡萄球菌的临床应用评价  

Clinical evaluation in detecting methicillin-resistant Staphylococci with cefoxitin disk diffusion method

作　　者：喻华[1] 刘小琦[1] 刘华[1] 黄文方[1] 黄湘宁[1] 周忠华[1] 杨楠[2] 

机构地区：[1]四川省医学科学院,成都610072 [2]四川省人民医院检验科,成都610072

出　　处：《国际检验医学杂志》2006年第12期1085-1087,共3页International Journal of Laboratory Medicine

摘　　要：目的用PCR法检测葡萄球菌的mecA基因为参比方法,评价头孢西丁纸片扩散法检测耐甲氧西林葡萄球菌(MRS)的临床应用价值。方法临床分离的163株葡萄球菌,分别用头孢西丁、苯唑西林纸片扩散法、PCR法检测mecA基因,以PCR扩增法检测mecA基因作为参比方法进行比较。结果163株临床分离的葡萄球菌经PCR法检测mecA基因,阳性率为81.0%,其中,耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)的发生率分别为74.1%和83.8%。头孢西丁、苯唑西林纸片扩散法用于检测MRSA与PCR法检测mecA基因有很好的一致性,其敏感性和特异性均为100.0%,而对于凝固酶阴性葡萄球菌,头孢西丁纸片扩散法比苯唑西林纸片扩散法检测MRS的敏感性和特异性高,敏感性分别为100.0%和94.3%,特异性分别为96.0%和88.0%。结论头孢西丁纸片扩散法检测耐甲氧西林葡萄球菌具有很高的灵敏度,但对于mecA基因阴性的凝固酶阴性葡萄球菌,用头孢西丁纸片法检测,约有5%菌株要误报为MRCNS。由于头孢西丁纸片扩散法操作简单,较苯唑西林纸片扩散法检出MRS的敏感度和特异性高,结果与PCR法检测mecA基因有很好的相关性,不需特殊仪器设备,可在临床微生物实验室常规开展。Objective To evaluate the clinical practicability of cefoxitin disk diffusion method in detecting methicillin-resistant Staphylococci. Methods 163 strains of clinically isolated Staphylococci were tested. The cefoxitin,oxacillin disk diffusion test and PCR amplification of mecA gene were performed simultaneously. The method of PCR was used as the golden standard. Results 163 strains of clinically isolated Staphylococci were tested by PCR. The positive ratio of mecA gene was 81.0%, The ocurrence rate of methicillin-resistant S. aureus （MRSA） and （ methicillin-resistant coagulase-negative Staphylococci （MRCNS） was 74.1% and 83.8%, respectively. The cefoxitin, oxacillin disk diffusion and PCR were high consistency in detecting mecA gene. Both sensitivity and specificity were 100% , But cefoxitin disk diffusion was better for methieillin-resistant coagulase-negative Staphylococci. The sensitivity was 100% and 96.0%, the specificity was 94.3% and 88.0%, respectively. Conclusion Cefoxitin disk diffusion has high sensitivity in detecting methicillin-resistant Staphylococci,but for methicillin-resistant coagulase-negative Staphylococci which mecA gene is negative,5% strain may be reported as MRCNS by mistake. Since cefoxitin disk diffusion method is simple,and has higer sensitivity and specificity than oxacillin disk diffusion method in detecting MRS , the result has good correlation with PCR in detecting mecA gene. It may be applied in clinical microbiology laboratory.

关 键 词：甲氧西林抗药性 头孢西丁 葡萄球菌属 微生物敏感性试验 

分 类 号：R446.5[医药卫生—诊断学] R450[医药卫生—临床医学]