Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), 28034 Madrid, Spain.
FASTinov, S.A., 4200-135 Porto, Portugal.
Int J Mol Sci. 2024 Jul 18;25(14):7888. doi: 10.3390/ijms25147888.
Carbapenemase-producing Enterobacterales are increasingly being recognized in nosocomial infections. The performance of a flow cytometry-based rapid assay for their detection and differentiation was evaluated. This is a disruptive phenotypic technology, phenotypic and growth-independent, that searches for the lesions produced by drugs acting on cells after a short incubation time. Overall, 180 Gram-negative bacteria were studied, and results were compared with those obtained molecularly by PCR and phenotypically by 'KPC, MBL and OXA-48 Confirm Kit'. This phenotypic method was used as reference for comparison purposes. Susceptibility to carbapenems (imipenem, meropenem, and ertapenem) was determined by standard broth microdilution. Overall, 112 isolates (62.2%) were carbapenemase producers, 41 KPCs, 36 MβLs, and 31 OXA-48, and 4 strains were KPC + MβL co-producers. Sixty-eight isolates were carbapenemase-negative. The percentage of agreement, sensitivity, and specificity were calculated according to ISO 20776-2:2021. The FASTinov assay showed 97.7% agreement with the reference method for carbapenemase detection. Discrepant flow cytometry results were obtained in four isolates compared with both reference and PCR results. The sensitivity and specificity of this new technology were 95.3% and 98.5%, respectively, for KPCs, 97.6% and 99.3% for MβLs, and 96.9% and 98% for OXA-48 detection. In conclusion, we describe a rapid flow cytometry assay with high accuracy for carbapenemase detection and the differentiation of various carbapenemases, which should impact clinical microbiology laboratories and patient management.
产碳青霉烯酶肠杆菌科越来越多地被认为是医院感染的原因。本文评估了一种基于流式细胞术的快速检测和区分方法的性能。这是一种具有突破性的表型技术，与表型和生长无关，它在短孵育时间后寻找作用于细胞的药物产生的病变。总体而言，研究了 180 株革兰氏阴性菌，并将结果与通过 PCR 分子学和“KPC、MBL 和 OXA-48 确证试剂盒”表型获得的结果进行了比较。该表型方法被用作比较的参考。通过标准肉汤微量稀释法测定碳青霉烯类（亚胺培南、美罗培南和厄他培南）的敏感性。总体而言，112 株（62.2%）为碳青霉烯酶产生菌，41 株为 KPC，36 株为 MβL，31 株为 OXA-48，4 株为 KPC+MβL 共产生菌。68 株为碳青霉烯酶阴性。根据 ISO 20776-2:2021 计算了符合率、敏感性和特异性。FASTinov 检测法对碳青霉烯酶检测的符合率为 97.7%，与参考方法一致。与参考和 PCR 结果相比，有 4 株分离株的流式细胞术结果不一致。该新技术对 KPC 的灵敏度和特异性分别为 95.3%和 98.5%，对 MβL 为 97.6%和 99.3%，对 OXA-48 为 96.9%和 98%。总之，我们描述了一种快速、准确的流式细胞术检测方法，用于检测和区分各种碳青霉烯酶，这将对临床微生物学实验室和患者管理产生影响。
