Detection of patients with intestinal colonization of carbapenem-resistant organisms (CRO), or more specifically carbapenemase-producing (CP) CRO, can prevent their transmission in healthcare facilities and aid with outbreak investigations. The objective of this work was to further develop and compare methods that combine selective culture and/or PCR to rapidly detect and recover CRO from fecal specimens. Molecularly characterized Gram-negative bacilli (n = 62) were used to spike fecal samples to establish limit of detection (LOD; n = 12), sensitivity (n = 28), and specificity (n= 21) for 3 methods to detect CP-CRO: direct MacConkey (MAC) plate and Xpert Carba-R (Cepheid) on growth, MAC broth and Carba-R testing of the broth, and direct testing by Carba-R. This was followed by a clinical study comparing methods in parallel for 286 fecal specimens. The LOD ranged from 10^2-10⁵ CFU/mL depending on the carbapenemase gene and method. Combined culture/PCR methods had a sensitivity of 100%, whereas direct Carba-R testing had a sensitivity of 96% for the detection of CP-CRO. All methods had specificities of 100%. The prevalence of CP-CRO (0.7%) and non-CP-CRO (5.2 %) were low in the clinical study, where all methods demonstrated 100% agreement. The three methods performed comparably in detecting CP-CRO. Direct Carba-R testing had a higher LOD than the combined selective culture methods, but this may be offset by its rapid turnaround time for detection of CP-CRO. The selective culture methods provide the benefit of simultaneously isolating CP-CRO in culture for follow-up testing and detecting non-CP-CRO.

检测耐碳青霉烯菌 (CRO) 或更具体地说是产碳青霉烯酶 (CP) CRO 的患者肠道定植，可以防止它们在医疗机构中传播，并有助于暴发调查。这项工作的目的是进一步开发和比较结合选择性培养和/或 PCR 的方法，以从粪便标本中快速检测和回收 CRO。分子特征的革兰氏阴性杆菌 (n = 62) 用于添加粪便样本，以确定 3 种检测 CP 方法的检测限 (LOD；n = 12)、灵敏度 (n = 28) 和特异性 (n = 21) -CRO：直接 MacConkey (MAC) 板和 Xpert Carba-R (Cepheid) 对生长、MAC 肉汤和 Carba-R 肉汤的测试，以及通过 Carba-R 的直接测试。随后进行了一项临床研究，比较了 286 份粪便样本的平行方法。^2- 10 ⁵ CFU/mL 取决于碳青霉烯酶基因和方法。联合培养/PCR 方法的灵敏度为 100%，而直接 Carba-R 检测对 CP-CRO 的检测灵敏度为 96%。所有方法的特异性均为 100%。临床研究中 CP-CRO (0.7%) 和非 CP-CRO (5.2%) 的流行率较低，所有方法均显示 100% 的一致性。这三种方法在检测 CP-CRO 方面的表现相当。直接 Carba-R 测试比组合选择性培养方法具有更高的 LOD，但这可能会被其检测 CP-CRO 的快速周转时间所抵消。选择性培养方法提供了在培养中同时分离 CP-CRO 以进行后续测试和检测非 CP-CRO 的好处。