Institut für Medizinische Mikrobiologie, Universität Zürich, 8006 Zürich, Switzerland.
J Antimicrob Chemother. 2017 Jul 1;72(7):1948-1954. doi: 10.1093/jac/dkx100.
This study evaluated the AID carbapenemase line probe assay (LPA) for the detection and identification of carbapenem resistance genes in Enterobacteriaceae and other Gram-negative bacilli (GNB) using bacterial cultures and DNA extracts directly from patient urine samples.
The AID carbapenemase LPA detects 13 different carbapenemase genes. Test probe accuracy was verified for using clinical Enterobacteriaceae isolates harbouring bla KPC , bla VIM , bla NDM , bla GIM , bla AIM , bla SPM , bla IMP and bla OXA-48 and a well-characterized set of Escherichia coli DH5α strains transformed with the vector plasmid pUC57- kan harbouring bla BIC , bla SIM , bla DIM , bla IMI-3 , bla IMI-1 and bla NMC-A . Sensitivity and specificity was determined by testing 151 clinical GNB strains previously characterized for the production of carbapenemase activity and carbapenemase genes. Direct detection of carbapenemase genes using the LPA was determined using 299 clinical urine specimens. Analytical sensitivity for detection in urine was determined by testing serial dilutions of bla KPC and bla NDM in clinical Klebsiella pneumoniae strains.
All carbapenemase gene probes showed 100% accuracy without cross-reactions. Sensitivity and specificity of the LPA using clinical isolates was 100% for each. Analytical sensitivity for detection of bla KPC and bla NDM in urine was 10 1 -10 2 cfu. The LPA detected carbapenemase genes in 20 urines, which were confirmed in 12 samples by conventional multiplex PCR. Remarkably, 0 of the 20 urines grew carbapenemase-suspicious GNB applying EUCAST recommendations.
The AID carbapenemase LPA is an accurate, sensitive and easy-to-use test for the detection and identification of carbapenemase genes, which can readily be implemented in any diagnostic laboratory.
本研究评估了 AID 碳青霉烯酶线探针分析（LPA）在直接从患者尿液样本中培养的细菌和 DNA 提取物中检测和鉴定肠杆菌科和其他革兰氏阴性菌（GNB）中碳青霉烯耐药基因的能力。
AID 碳青霉烯酶 LPA 检测 13 种不同的碳青霉烯酶基因。通过使用临床携带 bla KPC、bla VIM、bla NDM、bla GIM、bla AIM、bla SPM、bla IMP 和 bla OXA-48 的肠杆菌科分离株以及用携带 bla BIC、bla SIM、bla DIM、bla IMI-3、bla IMI-1 和 bla NMC-A 的质粒 pUC57-kan 转化的经过充分表征的大肠杆菌 DH5α 菌株的临床特征来验证测试探针的准确性。通过测试先前对碳青霉烯酶活性和碳青霉烯酶基因产生进行特征分析的 151 株临床 GNB 菌株来确定敏感性和特异性。通过对 299 份临床尿液标本进行 LPA 直接检测来确定对碳青霉烯酶基因的直接检测。通过测试 bla KPC 和 bla NDM 在临床肺炎克雷伯菌菌株中的系列稀释液来确定在尿液中检测的分析灵敏度。
所有碳青霉烯酶基因探针均无交叉反应，准确率达到 100%。LPA 对临床分离株的敏感性和特异性均为 100%。bla KPC 和 bla NDM 在尿液中的检测分析灵敏度分别为 10 1 -10 2 cfu。LPA 在 20 份尿液中检测到碳青霉烯酶基因，其中 12 份经传统多重 PCR 确证。值得注意的是，根据 EUCAST 建议，20 份尿液中有 0 份分离出碳青霉烯酶可疑的 GNB。
AID 碳青霉烯酶 LPA 是一种准确、敏感且易于使用的检测和鉴定碳青霉烯酶基因的检测方法，可在任何诊断实验室中方便地实施。
