Carrassai Richard Martins, Wilhelm Camila Mörschbächer, Tragnago Kellen Figueira, Echevarria Aymê Duarte, Barth Afonso Luís
Faculdade de Farmácia, Universidade Federal do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil; Laboratório de Pesquisa em Resistência Bacteriana (LABRESIS), Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil.
Laboratório de Pesquisa em Resistência Bacteriana (LABRESIS), Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas (PPGCF), Faculdade de Farmácia, Universidade Federal do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil.
J Microbiol Methods. 2025 Feb;229:107093. doi: 10.1016/j.mimet.2025.107093. Epub 2025 Jan 18.
Carbapenemase-producing Enterobacterales are a growing concern in public health. In order to rapidly determine the antimicrobial profile, the MALDI Biotyper - antibiotic susceptibility test rapid assay (MBT-ASTRA) was developed, based on the relative growth of bacteria in the presence of antibiotics. In this study, we added carbapenemase enzymatic inhibitors to the MBT-ASTRA and developed an adapted method named MALDI Biotyper - Phenotypic Identification Test Rapid Assay (MBT-PITRA) in order to perform a rapid and cost-effective phenotypic test to detect Klebsiella pneumoniae carbapenemase (KPC) and New Delhi metallo-beta-lactamase (NDM), including co-producers, in Enterobacterales. Fifty-nine clinical isolates of carbapenemase-producing Enterobacterales and 28 non-carbapenemase-producing isolates collected from 2013 to 2023 were assessed using this approach. The MBT-PITRA method involved incubating bacterial isolates with different solutions of meropenem plus enzymatic inhibitors, phenylboronic acid and/or ethylenediaminetetraacetic acid, followed by analysis using MALDI-TOF MS. Carbapenemase production was inferred based on relative growth (RG) values calculated from peak intensities in the presence and absence of enzymatic inhibitors. KPC-producing isolates presented 90 % (18/20) concordance, while isolates positive for NDM (16/16), KPC plus NDM (14/14) and negative (28/28) for carbapenemases were 100 % correctly identified. MBT-PITRA demonstrated to be a promising method for identification of carbapenemases. IMPORTANCE: The MBT-PITRA appears to be a promising method for the rapid detection of carbapenemases in Enterobacterales.
产碳青霉烯酶肠杆菌目细菌日益引起公共卫生领域的关注。为了快速确定抗菌谱，基于细菌在抗生素存在下的相对生长情况，开发了基质辅助激光解吸电离飞行时间质谱仪 - 抗生素敏感性试验快速检测法（MBT - ASTRA）。在本研究中，我们在MBT - ASTRA中添加了碳青霉烯酶抑制剂，并开发了一种改良方法，称为基质辅助激光解吸电离飞行时间质谱仪 - 表型鉴定试验快速检测法（MBT - PITRA），以便进行快速且经济高效的表型检测，以检测肠杆菌目中的肺炎克雷伯菌碳青霉烯酶（KPC）和新德里金属β - 内酰胺酶（NDM），包括共生产者。使用该方法对2013年至2023年收集的59株产碳青霉烯酶肠杆菌目临床分离株和28株非产碳青霉烯酶分离株进行了评估。MBT - PITRA方法包括将细菌分离株与美罗培南加酶抑制剂、苯硼酸和/或乙二胺四乙酸的不同溶液孵育，然后使用基质辅助激光解吸电离飞行时间质谱（MALDI - TOF MS）进行分析。根据在有和没有酶抑制剂的情况下从峰强度计算出的相对生长（RG）值推断碳青霉烯酶的产生情况。产KPC的分离株一致性为90%（18/20），而NDM阳性（16/16）、KPC加NDM阳性（14/14）和碳青霉烯酶阴性（28/28）的分离株均被100%正确鉴定。MBT - PITRA被证明是一种有前景的碳青霉烯酶鉴定方法。重要性：MBT - PITRA似乎是一种快速检测肠杆菌目中碳青霉烯酶的有前景的方法。
