High quinolone resistance rates were observed among oxyiminocephalosporin-resistant enterobacteria.In the present study, we searched for the prevalence of plasmid-mediated quinolone resistance (PMQR) genes within the 55 oxyiminocephalosporin-resistant enterobacteria collected in a previous survey.The main PMQR determinants were aac(6')-Ib-cr and qnrB, which had prevalence rates of 42.4% and 33.3%, respectively.The aac(6')-Ib-cr gene was more frequently found in CTX-M-15-producing isolates, while qnrB was homogeneously distributed among all CTX-M producers.