title: Expression of multidrug efflux pump genes acrAB-tolC, mdfA, and norE in Escherichia coli clinical isolates as a function of fluoroquinolone and multidrug resistance.
abstract: In a single quantitative study, we measured acrA, acrB, tolC, mdfA, and norE expression in Escherichia coli clinical isolates by using real-time PCR. acrA and acrB overexpression strongly correlated with fluoroquinolone and multidrug resistance; tolC, mdfA, and norE expression did not. The order of abundance of efflux pump transcripts in all fluoroquinolone-susceptible isolates was tolC (highest), then acrA and acrB, and then mdfA and norE. Our findings suggest acrAB overexpression is an indicator of multidrug resistance.
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030-3411, USA.
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Swick
authors.forename: Sonia K
authors.initials: SK
authors.lastname: Morgan-Linnell
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Carlson
authors.forename: Lynn
authors.initials: L
authors.lastname: Zechiedrich
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D024841:Fluoroquinolones / Q000494:pharmacology*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D024841:Fluoroquinolones; D008074:Lipoproteins; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C083497:AcrA protein, E coli; C083496:AcrB protein, E coli; C118438:Mdfa protein, E coli; C073126:tolC protein, E coli