Multiplex lateral flow immunochromatographic assay is an effective method to detect carbapenemases without risk of OXA-48-like cross reactivity

Abstract Background It is essential to detect carriers of carbapenemase-producing Enterobacterales in order to implement infection control measures. The objectives of this study was to evaluate the NG-Test® CARBA 5 (CARBA 5) assay for detection of five carbapenemases and to assess the cross reactivity of other OXA-type carbapenemases with the OXA-48-like specific antibodies. Methods A total of 197 Enterobacterales isolates were tested. To evaluate the cross reactivity, 73 carbapenem-resistant A. baumannii, harboring OXA-type variants, were tested. Polymerase chain reaction (PCR) served as gold standard for carbapenemase identification. Results Excellent agreement was found between PCR and CARBA 5, for all but one isolate. The single false positive result (a bla SME positive S. marcescens isolate) was incorrectly positive for bla OXA-48 by CARBA 5. No cross reactivity was observed. The sensitivity and specificity were 100.0% and 98.0%, respectively. Conclusions The CARBA 5 assay is highly sensitive and specific and is recommended as a tool for the detection of the main carbapenemases of interest in clinical microbiology laboratories