Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg, Franz-Josef-Strauß-Allee 11, D-93053 Regensburg, Germany.
German National Reference Laboratory for Multidrug-Resistant Gram-negative Bacteria, Department of Medical Microbiology, Ruhr-University Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
J Microbiol Methods. 2019 Jan;156:29-33. doi: 10.1016/j.mimet.2018.11.024. Epub 2018 Dec 3.
Recently, the CPO Detect panel for the detection of carbapenemase-producing, Gram-negative bacteria was introduced for the Phoenix semi-automated antimicrobial susceptibility testing system. The CPO Detect assay aims to detect carbapenemase activity (P/N test) and to type carbapenemase producers according to the Ambler classification (Ambler test). The P/N test-based detection of carbapenemase producers was 100% sensitive and 55.3% specific in the assessment of 57 carbapenemase-producing and 38 non-carbapenemase-producing Enterobacterales. False-positive test isolates in the P/N test arose from carbapenemase-non-producing, but carbapenem-non-susceptible isolates. In contrast, using the Ambler test-based approach for carbapenemase detection resulted in a specificity of 100% and a sensitivity of 79%. In order to improve the overall performance, we established an algorithm that additionally included the colorimetric β-CARBA assay as downstream test for P/N test-positive isolates, which remained un-typed in the Ambler test. This algorithm displayed an overall sensitivity and specificity of 98.3% and 100%, respectively. Our data demonstrate that the combination of the CPO Detect assay with the β-CARBA test allows for rapid detection and classification of carbapenemase-producing Enterobacterales.
最近，针对产碳青霉烯酶革兰氏阴性菌的 CPO Detect 检测板已被引入 Phoenix 半自动抗菌药物敏感性测试系统。CPO Detect 检测法旨在检测碳青霉烯酶活性（P/N 检测），并根据 Ambler 分类对产碳青霉烯酶的细菌进行分型（Ambler 检测）。在对 57 株产碳青霉烯酶肠杆菌科和 38 株非产碳青霉烯酶肠杆菌科的评估中，基于 P/N 检测的产碳青霉烯酶检测的敏感性为 100%，特异性为 55.3%。在 P/N 检测中出现的假阳性试验分离株来自产碳青霉烯酶但对碳青霉烯类药物不敏感的分离株。相比之下，使用基于 Ambler 检测的方法进行碳青霉烯酶检测的特异性为 100%，敏感性为 79%。为了提高整体性能，我们建立了一种算法，该算法还包括对 P/N 检测阳性但在 Ambler 检测中未分型的分离株进行下游β-CARBA 比色检测。该算法的总体敏感性和特异性分别为 98.3%和 100%。我们的数据表明，CPO Detect 检测法与β-CARBA 检测法的结合可实现产碳青霉烯酶肠杆菌科的快速检测和分型。
