In order to investigate the diagnostic performance characteristics of four phenotypic assays in detecting carbapenem-resistant Enterobacteriaceae (CRE), we collected the CRE strains from infected patients. The results of carbapenemase gene detection, bla_KPC-2, bla_OXA-23, bla_NDM-1, bla_NDM-4, bla_NDM-5, bla_IMP-4, and bla_IMP-8, were used as a standard to evaluate the performances of combined disk test (CDT), modified carbapenem inactivation method(mCIM)/EDTA-modified carbapenem inactivation method(eCIM), NG-Test CARBA 5 (CARBA), and color developing immunoassay (CDI). The compliance of phenotype results based on CDT, mCIM/eCIM, CARBA, and CDI with genetic detection results was 94% (231/247), 95% (235/247), 98% (242/247), and 99% (246/247), respectively. CDT demonstrated a low specificity for carbapenemase detection, low negative predictive value (NPV), and low sensitivity for metallo-β-lactamase (79%, 55%, and 88%, respectively); it also failed to accurately detect IMP. The mCIM/eCIM assay had serious problems in detecting OXA-23-like carbapenemases. The sensitivity and specificity of CARBA and CDI were higher than those of the first two methods. However, CARBA did not cover the detection of OXA-23, while CDI cannot detect IMP-8, resulting in low NPVs (70% and 88%, respectively). In conclusion, CARBA and CDI assays are highly accurate except individual rare genes and allow direct genotype detections. CDT and mCIM/eCIM assays are moderately accurate and can only distinguish serine-β-lactamases from metallo-β-lactamases. Laboratories should choose the appropriate method that meets their needs based on its characteristic.

为了研究四种表型检测在检测耐碳青霉烯类肠杆菌科细菌 (CRE) 中的诊断性能特征，我们收集了来自感染患者的 CRE 菌株。碳青霉烯酶基因检测结果，布拉_KPC-2 ,布拉_OXA-23 ,布拉_NDM-1 ,布拉_NDM-4 ,布拉_NDM-5 ,布拉_IMP-4和布拉_IMP-8, 被用作评估联合圆盘试验 (CDT)、改良碳青霉烯类灭活法 (mCIM)/EDTA 改良碳青霉烯类灭活法 (eCIM)、NG-Test CARBA 5 (CARBA) 和显色免疫分析的性能的标准。 CDI)。基于 CDT、mCIM/eCIM、CARBA 和 CDI 的表型结果与基因检测结果的符合性分别为 94%（231/247）、95%（235/247）、98%（242/247）和 99%（ 246/247），分别。CDT 对碳青霉烯酶检测的特异性低，阴性预测值 (NPV) 低，对金属-β-内酰胺酶的敏感性低（分别为 79%、55% 和 88%）；它也未能准确检测到 IMP。mCIM/eCIM 检测在检测 OXA-23 样碳青霉烯酶方面存在严重问题。CARBA和CDI的敏感性和特异性均高于前两种方法。然而，CARBA 未涵盖 OXA-23 的检测，而 CDI 无法检测 IMP-8，导致 NPV 较低（分别为 70% 和 88%）。总之，CARBA 和 CDI 检测除了个别稀有基因外都是高度准确的，并且可以直接检测基因型。CDT 和 mCIM/eCIM 检测准确度适中，只能区分丝氨酸-β-内酰胺酶和金属-β-内酰胺酶。实验室应根据其特点选择适合自己需要的方法。