High percentage of resistance to ciprofloxacin and qnrB19 gene identified in urinary isolates of extended-spectrum beta-lactamase-producing Escherichia coli in Madrid, Spain.

The presence of qnr genes in 191 extended-spectrum beta-lactamase-producing Escherichia coli from 2005, with 75% of resistance to ciprofloxacin, was evaluated. An SHV-12-producing E. coli carried qnrB19; both genes were transferred by conjugation. No qnrA- or qnrS-positive strains were detected. In addition, we identified 3 new parC mutations (S80W, E84R… (More)