title: Cloning and characterization of the Burkholderia vietnamiensis norM gene encoding a multi-drug efflux protein.
abstract: Polymyxin B-sensitive mutants in Burkholderia vietnamiensis (Burkholderia cepacia genomovar V) were generated with a mini-Tn5 encoding tetracycline resistance. One of the transposon mutants had an insertion in the norM gene encoding a multi-drug efflux protein. Expression of B. vietnamiensis norM in an Escherichia coli acrAB deletion mutant complemented its norfloxacin hypersensitivity, indicating that the protein functions in drug efflux. However, no effect on antibiotic sensitivity other than sensitivity to polymyxin B was observed in the B. vietnamiensis norM mutant. We demonstrate that increased polymyxin sensitivity in B. vietnamiensis was associated with the presence of tetracycline in the growth medium, a phenotype that was partially suppressed by expression of the norM gene.
authors.affiliation: Department of Microbiology and Immunology, University of Western Ontario, London, Canada N6A 5C1.
authors.forename: Christine C
authors.initials: CC
authors.lastname: Fehlner-Gardiner
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Valvano
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000378:metabolism / Q000494:pharmacology; D017920:Antiporters / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D019117:Burkholderia / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D003001:Cloning, Molecular; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D029968:Escherichia coli Proteins; D008969:Molecular Sequence Data; D009643:Norfloxacin / Q000378:metabolism / Q000494:pharmacology; D011113:Polymyxins / Q000378:metabolism / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D013752:Tetracycline / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D017920:Antiporters; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C114619:NorM protein, bacteria; D011113:Polymyxins; C491958:mdtK protein, E coli; D013752:Tetracycline; D009643:Norfloxacin