Pharmacodynamic activity of ertapenem versus genotypically characterized extended-spectrum -lactamase (ESBL)-, KPC- or NDM-producing Escherichia coli with reduced susceptibility or resistance to ertapenem using an in vitro model

Abstract

Once-daily dosing with 1 g of ertapenem was bactericidal against ESBL-producing E. coli with ertapenem MICs ≤ 0.5 mg/L and was bactericidal against strains with MICs of 1.0 mg/L, with regrowth in some strains. Ertapenem MICs of 2-8 mg/L resulted in early bactericidal activity followed by regrowth. Once-daily dosing with 2 g of ertapenem was bactericidal against strains with an MIC of 1.0 mg/L, but regrowth occurred in some strains with an ertapenem MIC of 2 mg/L.