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=11

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=<p>Carbapenem-resistant <italic>Acinetobacter</italic> spp. mainly <italic>Acinetobacter baumannii</italic> are frequently causing nosocomial infections with high mortality. In this study, the efficacy of the Eazyplex<sup>®</sup> SuperBug Complete A system, based on loop-mediated isothermal amplification (LAMP), to detect the presence of carbapenemases in <italic>Acinetobacter</italic> spp. directly from bronchoalveolar lavage (BAL) samples was assessed. A total of 22 <italic>Acinetobacter</italic> 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 that express carbapenemases (<italic>bla</italic><sub><italic>KPC</italic></sub>, <italic>bla</italic><sub><italic>NDM</italic></sub>, <italic>bla</italic><sub><italic>VIM</italic></sub>, <italic>bla</italic><sub><italic>OXA–48</italic></sub>, <italic>bla</italic><sub><italic>OXA–23</italic></sub>, <italic>bla</italic><sub><italic>OXA–40</italic></sub>, and <italic>bla</italic><sub><italic>OXA–58</italic></sub>). Negative BAL samples were identified, McFarland solutions were prepared from each of the 22 <italic>Acinetobacter</italic> strains and serial dilutions in saline solution were made to finally spike BAL samples to a concentration of 10<sup>2</sup> and 10<sup>3</sup> CFU/ml. Fifteen concentrations out of the 44 tested out did not provide detection of the carbapenemase-producing gene, all but one being at the lowest concentration tested at 10<sup>2</sup> CFU/ml; therefore, the limit of sensitivity is 10<sup>3</sup> 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 min with a sensitivity of 10<sup>3</sup> CFU/ml.</p>