title: A multiple-antibiotic resistance-independent active chloramphenicol efflux in an Escherichia coli clinical isolate.
abstract: The clinical isolate, Escherichia coli 1941, exhibits high resistance to chloramphenicol and tetracycline (minimum inhibitory concentrations of 512 micrograms/ml). Neither resistance is linked to the large conjugative plasmid present in the strain. The intracellular accumulation of radiolabeled chloramphenicol increased about 9-fold after the addition of the energy uncoupler carbonyl cyanide m-chlorophenol-hydrazone to an E. coli 1941 culture, indicating the presence of an active efflux mechanism. Sequence analysis and expression study suggested that the multiple-antibiotic resistance marRAB locus and the AcrAB drug-efflux pump were not involved in this active efflux of chloramphenicol.
authors.affiliation: INSERM CJF 96-06, Faculty of Medicine, Marseille, France.
authors.forename: A
authors.initials: A
authors.lastname: Bellaaj
authors.forename: M
authors.initials: M
authors.lastname: Mallea
authors.forename: C
authors.initials: C
authors.lastname: Bollet
authors.forename: C
authors.initials: C
authors.lastname: Belhadj
authors.forename: O
authors.initials: O
authors.lastname: Belhadj
authors.forename: K
authors.initials: K
authors.lastname: Ben-Mahrez
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism*; D002352:Carrier Proteins; D002701:Chloramphenicol / Q000378:metabolism*; D002702:Chloramphenicol Resistance / Q000502:physiology*; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics; D008074:Lipoproteins / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics; D026901:Membrane Transport Proteins; D008826:Microbial Sensitivity Tests; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D010957:Plasmids / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000900:Anti-Bacterial Agents; D002352:Carrier Proteins; D002701:Chloramphenicol; D017931:DNA Primers; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C083497:AcrA protein, E coli; C083496:AcrB protein, E coli; C080002:MarA protein, E coli