Evaluation of Multiple Methods for Detection of Gastrointestinal Colonization of Carbapenem-Resistant Organisms from Rectal Swabs

Rectal swabs from high-risk patients were screened for carbapenem-resistant organisms (CROs) using several methods. The direct MacConkey plate method was the most sensitive for CROs (95%), while chrom ID CARBA and the Check-Direct CPE screen assay were the most sensitive for the detection of carbapenemase-producing organisms (CPOs)(100%; all blaKPC). All methods had a specificity of >90% for CROs, and for CPOs, the specificity ranged from 85 to 98%. Broth enrichment methods performed poorly compared to direct inoculation methods, negating the need for the broth enrichment step.