title: The acrAB homolog of Haemophilus influenzae codes for a functional multidrug efflux pump.
abstract: Disruption of gene HI0894 or HI0895 in Haemophilus influenzae Rd, homologs of Escherichia coli acrAB multidrug efflux genes, caused hypersusceptibility to erythromycin, rifampin, novobiocin, and dyes such as ethidium bromide and crystal violet and increased accumulation of radioactive erythromycin, showing that these genes are expressed and contribute to the baseline level resistance of this organism through active drug efflux. The gene disruption did not produce detectable changes in susceptibility to several other antibiotics, possibly because rapid influx of small antibiotic molecules through the large H. influenzae porin channels counterbalances their efflux.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley 94720-3206, USA.
authors.forename: L
authors.initials: L
authors.lastname: Sánchez
authors.forename: W
authors.initials: W
authors.lastname: Pan
authors.forename: M
authors.initials: M
authors.lastname: Viñas
authors.forename: H
authors.initials: H
authors.lastname: Nikaido
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001693:Biological Transport, Active; D002352:Carrier Proteins; D004396:Coloring Agents / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology; D004352:Drug Resistance, Microbial / Q000235:genetics*; D004917:Erythromycin / Q000378:metabolism; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D006193:Haemophilus influenzae / Q000235:genetics* / Q000378:metabolism; D016623:Ion Pumps / Q000235:genetics*; 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; D016296:Mutagenesis; D017385:Sequence Homology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004396:Coloring Agents; D003902:Detergents; D004917:Erythromycin; D029968:Escherichia coli Proteins; D016623:Ion Pumps; 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