Department of Clinical Microbiology - CDB, Hospital Clínic, University of Barcelona, Barcelona, Spain.
Institute for Global Health (ISGlobal), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.
J Antimicrob Chemother. 2020 Jun 1;75(6):1453-1457. doi: 10.1093/jac/dkaa031.
To evaluate and compare the efficacy of real-time PCR (Xpert Carba-R) and loop-mediated isothermal amplification (Eazyplex® SuperBug CRE) for detecting carbapenemase carriage in Enterobacteriaceae directly from bronchoalveolar lavage (BAL).
Negative BAL samples were spiked with 21 well-characterized carbapenemase-producing Enterobacteriaceae strains to a final concentration of 102-104 cfu/mL. Xpert Carba-R (Cepheid, Sunnyvale, CA, USA), which detects five targets (blaKPC, blaNDM, blaVIM, blaOXA-48 and blaIMP-1), and the Eazyplex® SuperBug CRE system (Amplex-Diagnostics GmbH, Germany), which detects seven genes (blaKPC, blaNDM, blaVIM, blaOXA-48, blaOXA-181, blaCTXM-1 and blaCTXM-9), were evaluated for the detection of these genes directly from BAL samples.
Xpert Carba-R showed 100% agreement with carbapenemase characterization by PCR and sequencing for all final bacteria concentrations. Eazyplex® SuperBug CRE showed 100%, 80% and 27% agreement with PCR and sequencing when testing 104, 103 and 102 cfu/mL, respectively. False negative results for Eazyplex® SuperBug CRE matched the highest cycle threshold values for Xpert Carba-R. Hands-on time for both assays was about 15 min, but Eazyplex® SuperBug CRE results were available within 30 min, whereas Xpert Carba-R took around 50 min.
We here describe the successful use of two commercial diagnostic tests, Xpert Carba-R and Eazyplex® SuperBug CRE, to detect bacterial carbapenem resistance genes directly in lower respiratory tract samples. Our results could be used as proof-of-concept data for validation of these tests for this indication.
评估并比较实时 PCR（Xpert Carba-R）和环介导等温扩增（Eazyplex® SuperBug CRE）直接从支气管肺泡灌洗液（BAL）检测肠杆菌科中产碳青霉烯酶菌的疗效。
将 21 株特征明确的产碳青霉烯酶肠杆菌科菌株以 102-104 cfu/mL 的终浓度混入阴性 BAL 样本中。Xpert Carba-R（Cepheid，加利福尼亚州森尼韦尔）检测 5 个靶标（blaKPC、blaNDM、blaVIM、blaOXA-48 和 blaIMP-1），Eazyplex® SuperBug CRE 系统（德国 Amplex-Diagnostics GmbH）检测 7 个基因（blaKPC、blaNDM、blaVIM、blaOXA-48、blaOXA-181、blaCTXM-1 和 blaCTXM-9），评估这些基因直接从 BAL 样本中的检测情况。
Xpert Carba-R 与所有最终细菌浓度的 PCR 和测序鉴定产碳青霉烯酶结果完全一致。Eazyplex® SuperBug CRE 以 104、103 和 102 cfu/mL 的浓度进行测试时，与 PCR 和测序的符合率分别为 100%、80%和 27%。Eazyplex® SuperBug CRE 的假阴性结果与 Xpert Carba-R 的最高循环阈值相对应。两种检测方法的实际操作时间约为 15 分钟，但 Eazyplex® SuperBug CRE 结果可在 30 分钟内获得，而 Xpert Carba-R 则需要大约 50 分钟。
我们在此描述了两种商业诊断测试 Xpert Carba-R 和 Eazyplex® SuperBug CRE 成功地直接在下呼吸道样本中检测细菌碳青霉烯酶耐药基因。我们的结果可以用作这些测试针对该适应证的验证的概念验证数据。
