Performance of Carbapenemase Nordmann-Poirel, Modified Carbapenem Inactivation, and EDTA Carbapenem Inactivation Methods for Detecting Carbapenem-Resistant Isolates.

Infections caused by carbapenem-resistant (CRKP) are a major threat to public health. Timely detection of CRKP will help treat patients with appropriate antibiotics. This study aimed to evaluate the performance of the carbapenemase Nordmann-Poirel (CarbaNP), modified carbapenem inactivation (mCIM), and EDTA carbapenem inactivation (eCIM) methods for the detection of CRKP. We compared the results of the three assays with that of real-time PCR. In total, 195 isolates, including 150 carbapenem-resistant and 45 carbapenem-susceptible isolates, were investigated. Carbapenem-resistance genes, such as , , , , and , were identified using real-time PCR. Among the 150 CRKP isolates, 94 (62.7%) were positive for , 29 (19.3%) were positive for , and 27 (18%) were positive for both and . For detecting CRKP isolates, CarbaNP, mCIM, and eCIM showed 96.0%, 95.4%, and 96.7% sensitivity, respectively, and all three methods showed 100% specificity. All three phenotypic confirmatory tests are reliable for identifying CRKP, easy to perform, cost-effective, and can be incorporated with routine antibiotic susceptibility testing.