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.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Anti-Bacterial Agents / metabolism*
-
Carrier Proteins*
-
Chloramphenicol / metabolism*
-
Chloramphenicol Resistance / physiology*
-
DNA Primers
-
DNA, Bacterial / genetics
-
DNA-Binding Proteins / genetics
-
Escherichia coli / genetics
-
Escherichia coli / metabolism*
-
Escherichia coli Infections / microbiology*
-
Escherichia coli Proteins / genetics
-
Lipoproteins / genetics
-
Membrane Proteins / genetics
-
Membrane Transport Proteins
-
Microbial Sensitivity Tests
-
Multidrug Resistance-Associated Proteins
-
Plasmids / genetics
-
Reverse Transcriptase Polymerase Chain Reaction
Substances
-
AcrA protein, E coli
-
AcrB protein, E coli
-
Anti-Bacterial Agents
-
Carrier Proteins
-
DNA Primers
-
DNA, Bacterial
-
DNA-Binding Proteins
-
Escherichia coli Proteins
-
Lipoproteins
-
MarA protein, E coli
-
Membrane Proteins
-
Membrane Transport Proteins
-
Multidrug Resistance-Associated Proteins
-
Chloramphenicol