改良亚胺培南-EDTA纸片增效试验检测铜绿假单胞菌产金属酶表型

The phenotypic detection of metallo-beta-lactamase-producing Pseudomonas aeruginosa by modified imipenem-EDTA disk potentiation test

目的评估改良亚胺培南-乙二胺四乙酸(EDTA)纸片增效试验在检测铜绿假单胞菌(PA)产金属酶表型中的应用价值。方法收集95株耐碳青霉烯类药物PA,采用琼脂稀释法测定所有菌株对亚胺培南和美罗培南的最低抑菌浓度(MIC)值,聚合酶链反应(PCR)和DNA测序鉴定金属酶基因型,亚胺培南-EDTA纸片增效试验常规法和改良法检测金属酶表型。结果 95株耐碳青霉烯类药物PA对亚胺培南和美罗培南的耐药率分别为100.0%和71.6%;常规法敏感性、特异性、阳性预测值和阴性预测值分别是100.0%、96.6%、72.7%和100.0%,而改良法均为100.0%。结论改良亚胺培南-EDTA纸片增效试验可能是一种检测PA产金属酶表型的有效方法。

Objective To evaluate the modified imipenem-ethylene diamine tetraacetic acid （EDTA） disk potentiation test for the phenotypic detection of metallo-beta-lactamase-producing Pseudomonas aeruginosa （PA）. Methods A total of 95 carbapenem-resistant PA were collected. The minimum inhibition concentrations （MIC） of imipenem and meropenem were determined by agar dilution method. Polymerase chain reaction （ PCR ） and DNA sequencing were used for the identification of metallo-beta-lactamase genotypes. The phenotypie detection of metallo- beta-laetamase was done by conventional and modified imipenem-EDTA disk potentiation test. Results The resistance rates of imipenem and meropenem were 100.0% and 71.6% among these 95 carbapenem-resistant PA. The sensitivity, specificity, positive predictive value and negative predictive value of conventional test were 100.0% , 96.6% , 72.7% and lO0.0%, respectively. Those of modified test were all 100.0%. Conclusions The modified imipenem-EDTA disk potentiation test could be an effective method for the phenotypic detection of metallo-beta-lactamase-producing PA.