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 3...

Fluoroquinolone treatment failure has been reported in patients with nalidixic acid-resistant Salmonella infections. Both chromosomal- and plasmid-mediated quinolone-resistance mechanisms have been described. The objective of this study was to identify the prevalence of these mechanisms in a collection of 41 Salmonella spp. clinical isolates causing acute gastroenteritis, obtained in the Hospit...

BACKGROUND AND OBJECTIVES The ciprofloxacin resistance of Klebsiella (K.) pneumoniae is mediated primarily through alterations in type II topoisomerase (gyrA) gene and plasmid-mediated quinolone resistance-conferring genes (qnr). This study aimed to define the prevalence of plasmid-mediated quinolone resistance-conferring genes (qnr) and type II topoisomerase (gyrA) alterations of a population ...

Background: Plasmid mediated quinolone resistance (PMQR) has been shown to play an important role in resistance not only to quinolones, but also β-lactams and aminoglycosides. In fact, qnr genes are frequently carried along with β-lactamase determinants on the same plasmids. We studied the prevalence of qnrA, qnrB, qnrS and aac(6’)-Ib-cr genes among quinolone and cephalosporin resistant clinica...