Csiki-Fejer Edith, Traczewski Maria, Procop Gary W, Davis Thomas E, Hackel Meredith, Zambardi Gilles
bioMérieux, Inc.Hazelwood, Missouri, USA.
Clinical Microbiology Institute, Inc.Wilsonville, Oregon, USA.
J Clin Microbiol. 2025 Sep 10;63(9):e0044925. doi: 10.1128/jcm.00449-25. Epub 2025 Aug 1.
The objective of the present study was to evaluate the VITEK 2 antimicrobial susceptibility test (AST) for Gram-negative (GN) plazomicin performance using the VITEK 2 and VITEK 2 Compact Systems in clinical settings and to demonstrate its equivalence to the Clinical and Laboratory Standards Institute (CLSI) broth microdilution (BMD) technique. The clinical study conducted at four external sites followed the requirements detailed in the US Food and Drug Administration (FDA) and International Standards Organization (ISO) guidance documents and included clinical, challenge, quality, and reproducibility studies. In this multisite study, a total of 979 Enterobacterales isolates were tested. The VITEK 2 card minimum inhibitory concentration (MIC) results were compared with the reference BMD MIC results. The performance following ISO criteria indicated Essential Agreement (EA) = 97.8% and showed that VITEK 2 plazomicin MIC results for Enterobacterales tend to be in exact agreement when compared with the CLSI BMD reference method, except for when MICs tend to be in exact agreement or at least one doubling dilution lower. The analysis was also performed following the FDA criteria using the breakpoints defined by the FDA: ≤2 susceptible (S), 4 intermediate (I), and ≥8 resistant (R) for Enterobacterales. The analysis showed the following performance: EA = 98.7%, category agreement (CA) = 99.4%, and major errors (ME) = 0.1%, with no very major errors (VME) present. There are three species, , and for which the trend is ≥ 30% and therefore addressed as a note in the US label. The plazomicin test met the ISO and FDA criteria of ≥95% reproducibility and ≥95% quality control (QC) results within acceptable ranges for QC organisms.IMPORTANCEThe VITEK 2 AST-GN plazomicin test is a new, automated alternative to the BMD reference method for determining minimum inhibitory concentrations (MIC) of Enterobacterales, expanding the range of automatic AST testing.
本研究的目的是在临床环境中使用VITEK 2和VITEK 2 Compact系统评估VITEK 2对革兰氏阴性（GN）普拉佐米星的抗菌药敏试验（AST）性能，并证明其与临床和实验室标准协会（CLSI）肉汤微量稀释（BMD）技术等效。在四个外部地点进行的临床研究遵循了美国食品药品监督管理局（FDA）和国际标准化组织（ISO）指导文件中详述的要求，包括临床、挑战、质量和可重复性研究。在这项多地点研究中，共检测了979株肠杆菌科分离株。将VITEK 2卡最低抑菌浓度（MIC）结果与参考BMD MIC结果进行比较。按照ISO标准的性能表明基本一致率（EA）=97.8%，并且表明，与CLSI BMD参考方法相比，VITEK 2对肠杆菌科的普拉佐米星MIC结果往往完全一致，除了MIC往往完全一致或至少低一个稀释倍数的情况。还按照FDA标准，使用FDA定义的断点进行分析：肠杆菌科≤2为敏感（S），4为中介（I），≥8为耐药（R）。分析显示了以下性能：EA = 98.7%，类别一致率（CA）= 99.4%，主要错误（ME）= 0.1%，无极重大错误（VME）。有三个菌种，即 、 和 ，其趋势≥30%，因此在美国标签中作为注释提及。普拉佐米星试验在QC微生物的可接受范围内符合ISO和FDA标准的≥95%可重复性和≥95%质量控制（QC）结果。重要性VITEK 2 AST - GN普拉佐米星试验是一种用于确定肠杆菌科最低抑菌浓度（MIC）的新型自动化替代BMD参考方法，扩大了自动AST检测的范围。
