Metallo-β-lactamase resistance in Enterobacteriaceae is an artefact of currently utilized antimicrobial susceptibility testing methods

Abstract

Results indicate that meropenem in vivo efficacy is best represented by the pharmacodynamic profile generated using MICs determined in zinc-depleted media for MBL-producing Enterobacteriaceae. These translational data suggest that the use of conventional CAMHB for MBL susceptibility testing is inappropriate in distinguishing meaningful in vivo resistance given that zinc concentrations are supraphysiological in conventional CAMHB and negligible at infection sites.