Multicenter evaluation of the RAPIDEC ® CARBA NP assay for the detection of carbapenemase production in clinical isolates of Enterobacterales and Pseudomonas aeruginosa

The objective was to evaluate the performance of the RAPIDEC ® CARBA NP assay (RAPIDEC), a screening assay that utilizes a pH indicator to detect carbapenem hydrolysis within 2 h. A multicenter study evaluated 306 clinical bacterial strains of Enterobacterales (n = 257) andPseudomonas aeruginosa (n = 49). The RAPIDEC was compared to a composite reference standard—the Clinical Laboratory Standards Institute (CLSI) Carba NP assay, PCR for specific carbapenemase genes (blaKPC,blaNDM,blaOXA-48-like,blaVIM andblaIMP), and phenotypic carbapenem susceptibility testing. The assay was evaluated using two culture incubation times for the bacterial isolates: “routine”(cultures incubated 18-24 h) and “short” (cultures incubated 4-5 h). For the routine incubation, the overall percent agreement was 98.7% with a positive percent agreement (PPA) of 99.6% and a negative percent agreement (NPA) of 97.4%; there were five false positives and one false negative. For the short incubation, the overall percent agreement was 98.0% with a PPA of 98.5% and a NPA of 97.3%; there were five false positives and four false negatives. RAPIDEC results for theP. aeruginosa isolates were 100% concordant with the reference standard for both incubation times. The RAPIDEC assay is an accurate and rapid ( ≤ 2 h) assay for the detection of the most common carbapenemases in clinical isolates. Growth from a short incubation culture may be used to reliably detect carbapenemase production in ...
Source: European Journal of Clinical Microbiology and Infectious Diseases - Category: Microbiology Source Type: research