金黄色葡萄球菌β-内酰胺酶表型检测方法比较  

Comparison of phenotypic methods for β-lactamase detection in Staphylococcus aureus

作　　者：陆瀚文 周万青[1] 张之烽[1] 沈瀚[1] LU Hanwen;ZHOU Wanqing;ZHANG Zhifeng;SHEN Han(Department of Clinical Laboratory,Nanjing Drum Tower Hospital,Nanjing University School of Medicine,Nanjing 210008,Jiangsu,China)

机构地区：[1]南京大学医学院附属鼓楼医院检验科,江苏南京210008

出　　处：《检验医学》2019年第2期169-172,共4页Laboratory Medicine

基　　金：南京市医学科技发展资金资助项目(QRX17143)

摘　　要：目的评价几种金黄色葡萄球菌β-内酰胺酶表型检测方法的差异。方法收集自动化仪器检测青霉素最小抑菌浓度(MIC)≤0.12和≥0.25μg/mL的金黄色葡萄球菌38株和15株。分别采用青霉素抑菌圈边缘试验(P1、P10)、头孢硝噻吩显色试验和"四叶草"试验检测β-内酰胺酶。采用聚合酶链反应(PCR)扩增blaZ基因,并以基因检测方法为标准,评价几种检测方法的差异。结果 38株MIC≤0.12μg/mL的菌株中有2株抑菌圈直径(P10)为27 mm。检出blaZ基因阳性菌株15株,分别为2株青霉素MIC=0.12μg/mL和13株青霉素MIC≥0.25μg/mL的菌株。15株blaZ基因检测阳性菌株青霉素抑菌圈边缘试验均为阳性,敏感性为100%;头孢硝噻吩显色试验和"四叶草"试验阳性各14株,敏感性为93.3%。38株blaZ基因检测阴性的菌株中,"四叶草"试验阳性3株,特异性为92.1%;头孢硝噻吩显色试验和青霉素抑菌圈边缘试验阳性各为2株,特异性为94.7%。结论几种常见β-内酰胺酶表型检测方法均具有较高的敏感性和特异性,临床可根据实际需求进行选择。Objective To compare the phenotypic methods for β-lactamase detection in Staphylococcus aureus.Methods A total of 38 isolates with penicillin minimum inhibitory concentration(MIC)≤0.12 μg/mL and 15 isolates with penicillin MIC≥0.25 μg/mL were collected.Penicillin zone edge test(P1 and P10),nitrocefin test and clover test were used for β-lactamase detection.Polymerase reaction chain(PCR)was used for amplifying blaZ gene.The gene detection method was used as standard,and the difference among these methods were evaluated.Results Among the 38 isolates with MIC≤0.12 μg/mL,by penicillin zone edge test(P10),2 isolates produced 27 mm diameter of inhibition zone.Totally,15 isolates were positive for blaZ gene,including 2 isolates with MIC=0.12 μg/mL and 13 isolates with MIC≥0.25 μg/mL.Among the 15 isolates,the penicillin zone edge test showed all sensitive(100%).The nitrocefin test and clover test detected 14 isolates,and the sensitivity was 93.3%.There were 38 isolates being negative for blaZ gene,the nitrocefin test and penicillin zone edge test detected 2 isolates,and the specificity was 94.7%,while clover test detected 3 isolates,and the specificity was 92.1%.Conclusions The phenotypic methods mentioned above are specific and sensitive,which can be used according to clinical needs.

关 键 词：金黄色葡萄球菌 Β-内酰胺酶 最小抑菌浓度 blaZ基因 青霉素抑菌圈边缘试验 头孢硝噻吩显色试验 “四叶草”试验 

分 类 号：R446.5[医药卫生—诊断学]