title: Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
abstract: Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
authors.affiliation: Graduate School of Medical Science, Kitasato Institute University, Sagamihara, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Sugimura
authors.forename: Hideaki
authors.initials: H
authors.lastname: Maseda
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hanaki
authors.forename: Taiji
authors.initials: T
authors.lastname: Nakae
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation / Q000187:drug effects; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D011552:Pseudomonas Infections / Q000188:drug therapy; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D053038:Quorum Sensing / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D018942:Macrolides; D026901:Membrane Transport Proteins; C118598:MexA protein, Pseudomonas aeruginosa; C118597:MexB protein, Pseudomonas aeruginosa; C402263:OprM protein, Pseudomonas aeruginosa; D017963:Azithromycin