Pseudomonas aeruginosa remains a prominent nosocomial pathogen. Detection of carbapenemase-producing P. aeruginosa is vital to dictate antimicrobial therapy and infection control measures. A pragmatic, minimum inhibitory concentration-based algorithm using imipenem AND meropenem-resistant plus ceftazidime-, cefepime-, and piperacillin/tazobactam-nonsusceptible criterion was derived to guide carbapenemase testing in P. aeruginosa. This study was an assessment of the algorithm's test performance in a cohort of 985 nonduplicate P. aeruginosa isolates collected from 20 German medical laboratories. Susceptibility data were assessed in the algorithm using both Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) interpretations. Sensitivity and specificity were calculated to evaluate algorithm test performance. The original algorithm criteria resulted in high specificity (95–97%) using both CLSI and EUCAST criteria; however, it failed to capture five carbapenemase-harboring isolates testing piperacillin/tazobactam susceptibility (CLSI/EUCAST). Two carbapenemase-producing isolates were also meropenem susceptible per EUCAST. A modified algorithm utilizing imipenem OR meropenem-resistant plus ceftazidime and cefepime nonsusceptible, improved the sensitivity of the criteria without significantly compromising specificity (CLSI sensitivity/specificity: 96%/94% and EUCAST sensitivity/specificity: 96%/95%). Application of the modified algorithm criteria resulted in high sensitivity and specificity using both CLSI and EUCAST interpretations in a large cohort of clinical P. aeruginosa. Utilization of this algorithm can improve the efficiency of carbapenemase testing in the clinical laboratory.

中文翻译：

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铜绿假单胞菌直接碳青霉烯酶检测的表型算法评估：多中心德国队列验证

铜绿假单胞菌仍然是一种主要的医院病原体。检测产生碳青霉烯酶的铜绿假单胞菌对于决定抗菌治疗和感染控制措施至关重要。使用亚胺培南和耐美罗培南加头孢他啶、头孢吡肟和哌拉西林/他唑巴坦不敏感标准的实用的、基于最小抑制浓度的算法被推导出来指导铜绿假单胞菌中碳青霉烯酶的检测。这项研究是对算法在 985 个非重复铜绿假单胞菌队列中的测试性能的评估从 20 个德国医学实验室收集的分离物。在算法中使用临床和实验室标准协会 (CLSI) 和欧洲抗菌药物敏感性测试委员会 (EUCAST) 解释评估敏感性数据。计算敏感性和特异性以评估算法测试性能。使用 CLSI 和 EUCAST 标准的原始算法标准产生了高特异性（95-97%）；然而，它未能捕获测试哌拉西林/他唑巴坦敏感性 (CLSI/EUCAST) 的五种含有碳青霉烯酶的分离物。根据 EUCAST，两种产生碳青霉烯酶的分离物也对美罗培南敏感。使用亚胺培南或美罗培南耐药加头孢他啶和头孢吡肟不敏感的改进算法，在不显着影响特异性的情况下提高了标准的敏感性（CLSI 敏感性/特异性：96%/94% 和 EUCAST 敏感性/特异性：96%/95%）。修改后的算法标准的应用导致在大型临床队列中使用 CLSI 和 EUCAST 解释具有高灵敏度和特异性铜绿假单胞菌。利用该算法可以提高临床实验室碳青霉烯酶检测的效率。