Screening methods for intestinal carriage of multidrug-resistant Enterobacterales: interest of enrichment broth

Travel abroad is associated with a high risk of acquiring multidrug-resistant Enterobacterales (MDR-E) [i.e., extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) and plasmid-mediated-AmpC betalactamase-producing Enterobacterales (pAmpC-E)j. Here, we evaluated the utility of pre-enrichment and performance of screening for MDR-E using 2 different media (ChromID ESBL and biplate ESBL) from 574 traveler stool samples. ESBL-E and MDR-E were detected in 49% (281/574) and 51% (296/574) of travelers, respectively. Pre-enrichment improved the detection of ESBL-E and MDR-E by 11.7% and 12.5%, respectively, without decreasing specificity (88.4% versus 87.4% for ESBL-E screening and 92.4% versus 89.9% for MDR-E screening). Sensitivity of the biplate-ESBL agar was higher than for ChromID-ESBL for ESBL-E detection (92.9% versus 86.1%), but specificity was lower (642% versus 87.4%). Whereas pAmpC-E were all detected by biplate-ESBL, 96% (47/49) and 82% (40/49) were detected by ChromID-ESBL, respectively, with and without pre-enrichment. Pre-enrichment increases the performance of MDR-E screening, especially in individuals with low MDR-E digestive abundance. (C) 2020 Elsevier Inc. All rights reserved.