title: Imipenem and expression of multidrug efflux pump in Enterobacter aerogenes.
abstract: Imipenem is often used to treat intensive care unit patients infected by Enterobacter aerogenes, but it is leading to an increasing number of antibiotic resistant strains. Clinical isolates and imipenem resistant variants presented a high level of resistance to beta-lactam antibiotic group and to chemically unrelated drugs. We report here that imipenem selects strains which contain active efflux pumps ejecting various unrelated antibiotics including quinolones, tetracycline, and chloramphenicol. An increase of AcrA, an efflux pump component, was observed in the imipenem resistant variants. The overexpression of marA, involved in the genetic control of membrane permeability via porin and efflux pump expression, indicated the activation of the resistance genetic cascade in imipenem resistant variants.
authors.affiliation: Enveloppe Bactérienne, Perméabilité et Antibiotiques, EA2197, IFR48, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 05, Marseille cedex, France.
authors.forename: Charléric
authors.initials: C
authors.lastname: Bornet
authors.forename: Renaud
authors.initials: R
authors.lastname: Chollet
authors.forename: Monique
authors.initials: M
authors.lastname: Malléa
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Chevalier
authors.forename: Anne
authors.initials: A
authors.lastname: Davin-Regli
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Pagès
authors.forename: Claude
authors.initials: C
authors.lastname: Bollet
mesh_terms: D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000378:metabolism; D001693:Biological Transport, Active; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D021902:Enterobacter aerogenes / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D004756:Enterobacteriaceae Infections / Q000188:drug therapy / Q000382:microbiology; D014644:Genetic Variation; D006801:Humans; D015378:Imipenem / Q000493:pharmacokinetics / Q000494:pharmacology*; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D008565:Membrane Proteins; D015378:Imipenem