Acquisition of Carbapenem Resistance by Plasmid-Encoded-AmpC-Expressing Escherichia coli.

ABSTRACT: Although AmpC β-lactamases can barely degrade carbapenems, if at all, they can sequester them and prevent them from reaching their targets. Thus, carbapenem resistance in Escherichia coli and other Enterobacteriaceae can result from AmpC production and simultaneous reduction of antibiotic influx into the periplasm by mutations in the porin genes. Here we investigated the route and genetic mechanisms of acquisition of carbapenem resistance in a clinical E. coli isolate carrying bla_CMY-2 on a plasmid by selecting for mutants that are resistant to increasing concentrations of meropenem. In the first step, the expression of OmpC, the only porin produced in the strain under laboratory conditions, was lost, leading to reduced susceptibility to meropenem. In the second step, the expres

SUBMITTER: van Boxtel R 

PROVIDER: S-EPMC5192137 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature