Evaluation of the Oxoid Brilliance™ CRE Agar for the detection of carbapenemase-producing Enterobacteriaceae

The adequate detection of carbapenemase-producing Enterobacteriaceae (CPE) is essential for adequate antibiotic therapy and for infection control purposes, especially in an outbreak setting. Selective agars play an important role in the detection of CPE. The Oxoid Brilliance (TM) CRE Agar (Thermo Fisher Scientific) was evaluated for the detection of CPE using 255 non-repetitive Enterobacteriaceae isolates, including 95 CPE (36 KPC, 4 KPC plus VIM, 4 NDM, 6 GIM, 20 VIM, and 25 OXA-48-producing isolates). The sensitivity of the CRE agar for the detection of CPE was 94 % (89/95), but differed per carbapenemase gene (100 % for KPC, NDM, and GIM, 90 % for VIM, and 84 % for OXA-48-producing isolates). The specificity of the CRE agar was 71 %, due to the growth of AmpC- and/or ESBL-producing isolates. The CRE agar is a sensitive tool for the detection of KPC and metallo-carbapenemase-producing Enterobacteriaceae, although the detection of OXA-48 producers is less optimal. The relatively low specificity requires confirmation of carbapenemase production for isolates recovered from the CRE agar.