VmeAB, an RND-type multidrug efflux transporter in Vibrio parahaemolyticus.
Genes vmeA and vmeB, encoding a multidrug efflux transporter in the halophilic bacterium Vibrio parahaemolyticus, have been cloned using a drug-hypersusceptible Escherichia coli strain as the host. Cells of E. coli KAM33 (DeltaacrAB DeltaydhE) carrying the vmeAB region from V. parahaemolyticus conferred much higher MICs for a variety of antimicrobial agents than did control cells. Cells possessing VmeAB under energized conditions maintained very low intracellular concentrations of ethidium. This was as expected for an energy-dependent efflux system, and supports the notion--based on sequence homology--that VmeAB belongs to the resistance nodulation cell division (RND) family of multidrug efflux transporters. It is likely that VmeAB forms functional complexes with the outer-membrane protein TolC in E. coli, because introduction of vmeAB into cells of E. coli KAM43, which lacks the tolC gene, failed to elevate the MICs for any of the antimicrobial agents tested. Therefore, a V. parahaemolyticus homologue of tolC was also cloned, designated vpoC, and was introduced together with vmeAB into cells of E. coli KAM43. The MICs of all agents tested were raised and were comparable to the values observed in E. coli KAM33 harbouring a plasmid carrying vmeAB. Finally, a vmeAB-deficient mutant of V. parahaemolyticus was constructed (designated TM3). TM3 showed slightly higher susceptibility than the parental V. parahaemolyticus to some antimicrobial agents. Survival rate of the TM3 when exposed to deoxycholate decreased compared with that of the parent.
Department of Genome Applied Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700-8530, Japan.
Taira
T
Matsuo
Department of Molecular Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700-8530, Japan.
Katsuhiko
K
Hayashi
Department of Molecular Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700-8530, Japan.
Yuji
Y
Morita
Department of Molecular Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700-8530, Japan.
Motohiro
M
Koterasawa
Department of Molecular Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700-8530, Japan.
Wakano
W
Ogawa
Department of Molecular Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700-8530, Japan.
Tohru
T
Mizushima
Department of Molecular Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700-8530, Japan.
Tomofusa
T
Tsuchiya
Department of Genome Applied Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700-8530, Japan.
Teruo
T
Kuroda
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D003840:Deoxycholic Acid / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D004996:Ethidium / Q000378:metabolism / Q000494:pharmacology; D005798:Genes, Bacterial; D006801:Humans; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation / Q000235:genetics; D017422:Sequence Analysis, DNA; D014736:Vibrio parahaemolyticus / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; C073126:tolC protein, E coli; D003840:Deoxycholic Acid; D004996:Ethidium