Overexpression of marA, soxS, or acrAB produces resistance to triclosan in laboratory and clinical strains of Escherichia coli.
Triclosan (Irgasan) is a broad spectrum antimicrobial agent used in handsoaps, toothpastes, fabrics, and plastics. It inhibits lipid biosynthesis in Escherichia coli, probably by action upon enoyl reductase (FabI) (McMurry, L.M., Oethinger, M. and Levy, S.B. (1988) Nature 394, 531-532). We report here that overexpression of the multidrug efflux pump locus acrAB, or of marA or soxS, both encoding positive regulators of acrAB, decreased susceptibility to triclosan 2-fold. Deletion of the acrAB locus increased the susceptibility to triclosan approximately 10-fold. Four of five clinical E. coli strains which overexpressed marA or soxS also showed enhanced triclosan resistance. The acrAB locus was involved in the effects of triclosan upon both cell growth rate and cell lysis.
Center for Adaptation Genetics and Drug Resistance, Tufts University School of Medicine, Boston, MA 02111, USA. lmcmurry_tet@opal.tufts.edu
L M
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McMurry
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Oethinger
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Levy
D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002352:Carrier Proteins; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004352:Drug Resistance, Microbial / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029968:Escherichia coli Proteins; D015870:Gene Expression; D005798:Genes, Bacterial; D006801:Humans; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014260:Triclosan / Q000494:pharmacology*
D000891:Anti-Infective Agents, Local; D001426:Bacterial Proteins; D002352:Carrier Proteins; 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; D015534:Trans-Activators; D014157:Transcription Factors; D014260:Triclosan; C083497:AcrA protein, E coli; C083496:AcrB protein, E coli; C080002:MarA protein, E coli; C070725:SoxS protein, E coli