New plasmid-mediated fluoroquinolone efflux pump, QepA, found in an Escherichia coli clinical isolate.

ABSTRACT: Plasmid-mediated Qnr and AAC(6')-Ib-cr have been recognized as new molecular mechanisms affecting fluoroquinolone (FQ) resistance. C316, an Escherichia coli strain demonstrating resistance to various FQs, was isolated in Japan. Resistance to FQs was augmented in an E. coli CSH2 transconjugant, but PCR failed to detect qnr genes, suggesting the presence of novel plasmid-mediated FQ resistance mechanisms. Susceptibility tests, DNA manipulation, and analyses of the gene and its product were performed to characterize the genetic determinant. A novel FQ-resistant gene, qepA, was identified in a plasmid, pHPA, of E. coli C316, and both qepA and rmtB genes were mediated by a probable transposable element flanked by two copies of IS26. Levels of resistance to norfloxacin, ciprofloxacin, and enrofl

SUBMITTER: Yamane K 

PROVIDER: S-EPMC2043241 | biostudies-literature | 2007 Sep

REPOSITORIES: biostudies-literature