TbtABM, a multidrug efflux pump associated with tributyltin resistance in Pseudomonas stutzeri.
Tributyltin (TBT) is a toxic agent used in marine antifouling paints. Among the bacterial flora of a polluted harbor, TBT-resistant strains of Pseudomonas stutzeri have been isolated. In the strain 5MP1 (TBT minimum inhibitory concentration (MIC) > or =1000 mg l(-1)), TBT resistance was found to be associated with the presence of the operon tbtABM, homologous to the resistance-nodulation-cell division (RND) efflux pump family, as demonstrated by cloning in Escherichia coli. TbtABM exhibited the greatest homology (60.9-84.9%) with the TtgDEF and SrpABC systems, both involved in aromatic compound tolerance in P. putida. TbtABM conferred multidrug resistance (MDR) including to n-hexane, nalidixic acid, chloramphenicol, and sulfamethoxazole (antibiotic MICsx4 for the E. coli host strain carrying the operon). By polymerase chain reaction amplification and hybridization experiments, the presence of tbtABM was detected in the TBT-sensitive P. stutzeri 3MP1 (TBT MIC 25 mg l(-1)). However, the latter strain did not seem to express TbtABM. This is the first description of a MDR efflux pump in P. stutzeri, and of a new kind of substrate, TBT, for the RND family of transporters.
Jude
Florence
F
Laboratoire de Microbiologie, Université Victor Segalen Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux, France.
Arpin
Corinne
C
Brachet-Castang
Céline
C
Capdepuy
Michèle
M
Caumette
Pierre
P
Quentin
Claudine
C
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001693:Biological Transport, Active; D002701:Chloramphenicol / Q000378:metabolism / Q000494:pharmacology; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D024901:Drug Resistance, Multiple, Bacterial; D005798:Genes, Bacterial; D019450:Genes, MDR; D006586:Hexanes / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism*; D009268:Nalidixic Acid / Q000378:metabolism / Q000494:pharmacology; D009876:Operon; D016958:Pseudomonas putida; D044223:Pseudomonas stutzeri / Q000187:drug effects* / Q000502:physiology; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013420:Sulfamethoxazole / Q000378:metabolism / Q000494:pharmacology; D014220:Trialkyltin Compounds / Q000378:metabolism* / Q000494:pharmacology*
D001426:Bacterial Proteins; D002701:Chloramphenicol; D004269:DNA, Bacterial; D006586:Hexanes; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009268:Nalidixic Acid; D013420:Sulfamethoxazole; D014220:Trialkyltin Compounds; C026385:n-hexane; C011559:tributyltin