title: Contribution of the MexAB-OprM multidrug efflux system to the beta-lactam resistance of penicillin-binding protein and beta-lactamase-derepressed mutants of Pseudomonas aeruginosa.
abstract: Deletion of the mexAB-oprM multidrug efflux operon substantially compromised the beta-lactam resistance of beta-lactamase-derepressed mutants of Pseudomonas aeruginosa, although it had only a modest impact on resistance of a penicillin-binding protein mutant. This highlights the multifactorial nature of beta-lactam resistance in this organism. Moreover, the contribution of efflux to the net resistance seen in some beta-lactam-resistant mutants suggests that inhibition of MexAB-OprM-mediated drug efflux might be an effective approach to overcoming beta-lactam resistance attributed to efflux as well as to other mechanisms of beta-lactam resistance.
authors.affiliation: Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Srikumar
authors.forename: E
authors.initials: E
authors.lastname: Tsang
authors.forename: K
authors.initials: K
authors.lastname: Poole
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000502:physiology*; D004352:Drug Resistance, Microbial; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase / Q000502:physiology*; D009154:Mutation; D009876:Operon; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D001618:beta-Lactamases / Q000502:physiology*; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D047090:beta-Lactams; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D001618:beta-Lactamases