AUTHOR=Moreno-Morales Javier , Vergara Andrea , Kostyanev Tomislav , Rodriguez-Baño Jesús , Goossens Herman , Vila Jordi 

TITLE=Evaluation of a Loop-Mediated Isothermal Amplification Assay to Detect Carbapenemases Directly From Bronchoalveolar Lavage Fluid Spiked With Acinetobacter spp.

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 11 - 2020

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.597684

DOI=10.3389/fmicb.2020.597684

ISSN=1664-302X

ABSTRACT=Carbapenem-resistant Acinetobacter spp. mainly Acinetobacter baumannii are frequently causing nosocomial infections with high mortality. In this study, the efficacy of the Eazyplex® SuperBug Complete A system, based on loop-mediated isothermal amplification (LAMP), to detect the presence of carbapenemases in Acinetobacter spp. directly from bronchoalveolar lavage samples was assessed. A total of 22 Acinetobacter spp. strains producing OXA-23, OXA-40, OXA-58, NDM and IMP were selected. Eazyplex® SuperBug Complete A kit, used with the Genie II device, is a molecular diagnostics kit that detects a selection of genes which express carbapenemases (blaKPC, blaNDM, blaVIM, blaOXA-48, blaOXA-23, blaOXA-40 and blaOXA-58). Negative BAL samples were identified, McFarland solutions were prepared from each of the 22 Acinetobacter strains and serial dilutions in saline solution were made to finally spike BAL samples to a concentration of 102 and 103 CFU/ml. 10 concentrations out of the 38 tested out did not provide detection of the carbapenemase producing gene, all but one being at the lowest concentration tested at 102 CFU/ml, therefore, the limit of sensitivity is 103 CFU/ml. This assay represents the kind of advantages that investing in molecular diagnostics brings to the clinical practice, allowing the identification of carbapenemases in less than 30 minutes with a sensitivity of 103 CFU/ml.