Identification and molecular characterisation of CmeB, a Campylobacter jejuni multidrug efflux pump.
A multidrug efflux pump gene (cmeB) was identified from the published Campylobacter jejuni genome sequence. Secondary structural analysis showed that the gene encoded a protein belonging to the resistance nodulation cell division (RND) family of efflux transporters. The gene was inactivated by insertional mutagenesis. Compared with the wild-type strain (NCTC 11168), the resultant knockout strain (NCTC 11168-cmeB::kan(r)) displayed increased susceptibility to a range of antibiotics including beta-lactams, fluoroquinolones, macrolides, chloramphenicol, tetracycline, ethidium bromide, the dye acridine orange and the detergent sodium dodecyl sulfate. Accumulation of ciprofloxacin was increased in the knockout mutant, but carbonyl cyanide m-chlorophenyl hydrazone, a proton motive force inhibitor, had less effect upon ciprofloxacin accumulation in the knockout mutant compared with NCTC 11168. These data show that the identified gene encodes an RND-type multi-substrate efflux transporter, which contributes to intrinsic resistance to a range of structurally unrelated compounds in C. jejuni. This efflux pump has been named CmeB (for Campylobacter multidrug efflux).
Pumbwe
Lilian
L
Antimicrobial Agents Research Group, Division of Immunity and Infection, The Medical School, University of Birmingham, Birmingham B15 2TT, UK.
Piddock
Laura J V
LJ
D016123:Campylobacter jejuni / Q000502:physiology*; D002939:Ciprofloxacin / Q000378:metabolism; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D016296:Mutagenesis; D017433:Protein Structure, Secondary; D017422:Sequence Analysis, DNA
D026901:Membrane Transport Proteins; D002939:Ciprofloxacin