Comparison of the Performance of Two Rapid Immunochromatographic Methods for the Detection of Carbapenemase Genes among Carbapenem-Resistant Enterobacterales Clinical Strains

Abstract A rapid and accurate detection of carbapenemases for Enterobacterales isolates is crucial to the selection of antibiotics and the control of hospital infection. This study aimed to evaluate the performance of two immunochromatographic methods, NG-Test Carba 5 (Carba 5) and Goldstream Carbapenem-resistant K.N.I.V.O. Detection K-Set (K-Set), for detecting five major carbapenemases genes (blaKPC, blaNDM, blaIMP, blaOXA−48−like, and blaVIM). Carbapenemase genes were confirmed by PCR. In this study, 245 carbapenem-resistant Enterobacterales(CRE) strains were included, 96.7% of which produced carbapenemase. 58.2% of Klebsiella pneumoniae producing KPC carbapenemase was the most common CRE. NDM-producing Klebsiella pneumoniae accounted for 30.4%. Significantly, NDM-type are the primary carbapenemase among Escherichia coli and Enterobacter cloacae strains, accounting for 46 (93.9%) and 20 (83.3%) respectively. The performance of two methods showed excellent results in the carbapenemase detection with an overall specificity and sensitivity values both > 99%. Specially, one KPC-carbapenemase of K. pneumonia was accurately detected by the K-Set, but failed detected by Carba 5, since it harbored a novel blaKPC gene with a point mutation (A to G) at nucleotide position 787 compared with the blaKPC−33 gene. In conclusion, as simple, rapid and accurate diagnostic, these two methods are suitable for the carbapenemase genes detection in routine microbiology laboratories, providing an important basis for clinical rational selection of antibiotics.