Determining the Optimal Carbapenem MIC That Distinguishes Carbapenemase-Producing and Non-Carbapenemase-Producing Carbapenem-Resistant Enterobacteriaceae

Carbapenemase-producing (CP) Enterobacteriaceae are largely responsible for the rapid spread of carbapenem-resistant Enterobacteriaceae (CRE). Distinguishing CP-CRE from non-CP-CRE has important infection control implications. In a cohort of 198 CRE isolates, for isolates that remained susceptible or intermediate to some carbapenem antibiotics, an ertapenem MIC of 0.5 μg/ml and meropenem, imipenem, and doripenem MICs of 2 μg/ml were best able to distinguish CP-CRE from non-CP-CRE isolates.