Gu Danxia, Yan Zelin, Cai Chang, Li Jiaping, Zhang Yanyan, Wu Yuchen, Yang Jiaxing, Huang Yonglu, Zhang Rong, Wu Yongning
Laboratory Medicine Center, Department of Clinical Laboratory, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou 310014, China.
Department of Clinical Laboratory, Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou 310009, China.
Antibiotics (Basel). 2023 Feb 2;12(2):300. doi: 10.3390/antibiotics12020300.
Carbapenem-resistant Enterobacterales (CRE) are increasingly recognized as an urgent public health concern. The rapid and accurate identification of carbapenemases could provide insights into antimicrobial therapy and infection control. In this study, we evaluated the efficacy of three different methods, including the NG-test Carba 5, colloidal gold immunoassay (CGI) test, and Xpert Carba-R assay, for the rapid detection of five carbapenemases (KPC, NDM, IMP, OXA-48, and VIM). A total of 207 Gram-negative strains collected from patients and hospital sewages were tested. The presence or absence of carbapenemase genes in the whole-genome sequences was used as the gold standard for evaluating the accuracy of the above-mentioned three methods. Among the 192 strains carrying only one carbapenemase gene, the accuracies of the NG-Test Carba 5, CGI test, and Xpert Carba-R were 96.88% (95% CI, 93.01-98.72%), 96.88% (95% CI, 93.01-98.72%), and 97.92% (95% CI, 94.41-99.33%), respectively. Xpert Carba-R was able to detect all 13 types of KPC variants, including KPC-2, KPC-3, KPC-25, KPC-33, KPC-35, KPC-51, KPC-52, KPC-71, KPC-76, KPC-77, KPC-78, KPC-93, and KPC-123, with a detection sensitivity of 100.00% (95% CI, 96.50-100.00%), a specificity of 100.00% (95% CI, 92.38-100.00%), and a κ index of 1.00. For IMP, Carba 5 was superior to the other two methods, with a sensitivity of 100% (95% CI, 71.66-100.00%), a specificity of 100% (95% CI, 97.38-100.00%), and a κ index of 1.00. For the remaining 15 strains carrying two or three kinds of carbapenemase genes, Carba 5 performed the best, which accurately identified all the target genes, followed by Xpert Carba-R (12/15, 80.00%) and the CGI test (10/15, 66.67%). Therefore, all three assays demonstrated reliable performances in carbapenemase detection, and Xpert Carba-R should be recommended for the detection of KPC variants, especially for patients at a high risk of infections caused by ceftazidime/avibactam-resistant strains. IMPORTANCE: CRE was listed as one of the top three pathogens that are in critical need of new antibiotics by the WHO. The rapid and accurate identification of carbapenemases is important for antimicrobial therapy and infection control. In recent years, new beta-lactam/beta-lactamase inhibitor combinations such as ceftazidime/avibactam (CZA) have been approved by the Food and Drug Administration (FDA) to cope with CRE challenges. CZA was effective against class A, class C, and some class D enzymes such as OXA-48-like. However, CZA-resistant KPC variants emerged at an alarming speed, which posed a new challenge for the accurate identification of KPC variants. In this study, we evaluated the performance of two lateral flow immunochromatographic assays, namely, NG-test Carba 5 and the CGI test, and the automated real-time quantitative PCR Xpert Carba-R in the rapid detection of carbapenemases. Notably, 13 types of KPC variants were enrolled in this study, which covered most KPC variants discovered in China. Carba-R was superior to NG-teat Carba 5 and the CGI test; it was able to detect all of the included KPC variants, including KPC-2, KPC-3, KPC-25, KPC-33, KPC-35, KPC-51, KPC-52, KPC-71, KPC-76, KPC-77, KPC-78, KPC-93, and KPC-123.
耐碳青霉烯类肠杆菌科细菌（CRE）日益被视为一个紧迫的公共卫生问题。快速准确地鉴定碳青霉烯酶可为抗菌治疗和感染控制提供见解。在本研究中，我们评估了三种不同方法，包括NG-test Carba 5、胶体金免疫分析（CGI）试验和Xpert Carba-R检测法，用于快速检测五种碳青霉烯酶（KPC、NDM、IMP、OXA-48和VIM）的效果。共检测了从患者和医院污水中收集的207株革兰氏阴性菌株。全基因组序列中碳青霉烯酶基因的有无被用作评估上述三种方法准确性的金标准。在仅携带一种碳青霉烯酶基因的192株菌株中，NG-Test Carba 5、CGI试验和Xpert Carba-R的准确率分别为96.88%（95%CI，93.01 - 98.72%）、96.88%（95%CI，93.01 - 98.72%）和97.92%（95%CI，94.41 - 99.33%）。Xpert Carba-R能够检测所有13种KPC变体，包括KPC-2、KPC-3、KPC-25、KPC-33、KPC-35、KPC-51、KPC-52、KPC-71、KPC-76、KPC-77、KPC-78、KPC-93和KPC-123，检测灵敏度为100.00%（95%CI，96.50 - 100.00%），特异性为100.00%（95%CI，92.38 - 100.00%），κ指数为1.00。对于IMP，Carba 5优于其他两种方法，灵敏度为100%（95%CI，71.66 - 100.00%），特异性为100%（95%CI，97.38 - 100.00%），κ指数为1.00。对于其余携带两种或三种碳青霉烯酶基因的15株菌株，Carba 5表现最佳，能准确鉴定所有目标基因，其次是Xpert Carba-R（12/15，80.00%）和CGI试验（10/15，66.67%）。因此，所有三种检测方法在碳青霉烯酶检测中均表现出可靠的性能，对于KPC变体的检测，应推荐使用Xpert Carba-R，尤其是对于由头孢他啶/阿维巴坦耐药菌株引起感染风险较高的患者。重要性：CRE被世界卫生组织列为最急需新型抗生素的三大病原体之一。快速准确地鉴定碳青霉烯酶对抗菌治疗和感染控制至关重要。近年来，新型β-内酰胺/β-内酰胺酶抑制剂组合如头孢他啶/阿维巴坦（CZA）已获美国食品药品监督管理局（FDA）批准，以应对CRE带来的挑战。CZA对A类、C类以及一些D类酶如OXA-48样酶有效。然而，耐CZA的KPC变体以惊人的速度出现，这对KPC变体的准确鉴定提出了新的挑战。在本研究中，我们评估了两种侧向流动免疫层析检测方法，即NG-test Carba 5和CGI试验，以及自动化实时定量PCR Xpert Carba-R在快速检测碳青霉烯酶方面的性能。值得注意的是，本研究纳入了13种KPC变体，涵盖了在中国发现的大多数KPC变体。Carba-R优于NG-teat Carba 5和CGI试验；它能够检测所有纳入的KPC变体，包括KPC-2、KPC-3、KPC-25、KPC-33、KPC-35、KPC-51、KPC-52、KPC-71、KPC-76、KPC-77、KPC-78、KPC-93和KPC-123。
