title: Modification of outer membrane protein profile and evidence suggesting an active drug pump in Enterobacter aerogenes clinical strains.
abstract: Two clinical strains of Enterobacter aerogenes that exhibited phenotypes of multiresistance to beta-lactam antibiotics, fluoroquinolones, chloramphenicol, tetracycline, and kanamycin were investigated. Both strains showed a porin pattern different from that of a susceptible strain, with a drastic reduction in the amount of the major porin but with an apparently conserved normal structure (size and immunogenicity), together with overproduction of two known outer membrane proteins, OmpX and LamB. In addition, the full-length O-polysaccharide phenotype was replaced by a semirough Ra phenotype. Moreover, in one isolate the intracellular accumulation of chloramphenicol was increased in the presence of the energy uncoupler carbonyl cyanide m-chlorophenylhydrazone, suggesting an energy-dependent efflux of chloramphenicol in this strain. The resistance strategies used by these isolates appear to be similar to that induced by stress in Escherichia coli cells.
authors.affiliation: EA2197-IFR 48, Faculté de Médecine, 13385 Marseille Cedex 05. UMR 5048, CNRS, U554 INSERM, 34090 Montpellier, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Gayet
authors.forename: Renaud
authors.initials: R
authors.lastname: Chollet
authors.forename: Gérard
authors.initials: G
authors.lastname: Molle
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Pagès
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Chevalier
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000032:analysis* / Q000737:chemistry / Q000502:physiology; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002463:Cell Membrane Permeability; D002701:Chloramphenicol / Q000378:metabolism; D024881:Drug Resistance, Bacterial; D021902:Enterobacter aerogenes / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D029968:Escherichia coli Proteins; D006801:Humans; D006867:Hydrolases; D018272:Porins; D011991:Receptors, Virus / Q000032:analysis
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D018272:Porins; D011991:Receptors, Virus; C016532:maltoporins; C482905:OmpX protein, E coli; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D002701:Chloramphenicol; D006867:Hydrolases