Nontyphoidal Salmonella enterica strains with a nonclassical quinolone resistance phenotype were isolated from patients returning from Thailand or Malaysia to Finland. A total of 10 isolates of seven serovars were studied in detail, all of which had reduced susceptibility (MIC > or = 0.125 microg/ml) to ciprofloxacin but were either susceptible or showed only low-level resistance (MIC < or = 32...

background and aims: extended-spectrum β-lactamase (esbl) producing gram negative bacteria are resistant to penicillins, narrow and extended-spectrum cephalosporins, and aztreonam; also they are frequently resistant to trimethoprim-sulfamethoxazole, aminoglycosides, and quinolones. this study aimed to investigate the prevalence of plasmid-mediated quinolone resistance (pmqr) determinants qnra, ...

Sir, Chromosomal mutations in the topoisomerase II gene gyrA and altered drug accumulation were considered to be the only mechanisms of quinolone resistance until 1998, when the plasmidmediated quinolone resistance gene, qnrA, was described in an isolate of Klebsiella pneumoniae. Since then, other plasmidborne resistance genes, qnrB, qnrS (and their variants), aac(60)-Ib-cr and qepA, have been ...

Sir, Fluoroquinolones are broad-spectrum antibacterial agents commonly used in clinical practice. When quinolones became widely used, bacterial resistance to them emerged rapidly and, over the past three decades, resistance has continued to increase. In Gram-negative bacteria, quinolone resistance is due primarily to mutations in chromosomal genes encoding quinolone targets DNA gyrase and topoi...

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 clinical...

conclusions ctx-m was the most prevalent esbl genotype in uropathogenic e. coli (upec) isolated from uti. in addition, a high frequency of qnr genes among esbl-producing e. coli was identified in this study. in order to avoid treatment failures, we recommend using phenotypic and molecular methods to diagnose these enzymes and qnr genes. results the highest sensitivity was seen to imipenem (96.7...

INTRODUCTION Although independently acquired, plasmid-mediated quinolone resistance appears to be linked with extended-spectrum or AmpC-type beta-lactamases. Since no data are available in African countries, the prevalence of qnr genes at the University Hospital Ibn Rochd, Casablanca, Morocco, was investigated. METHODOLOGY Between October 2006 and March 2007, the following 39 randomly selecte...

Seven hundred fifty-one Escherichia coli clinical isolates collected from 140 Japanese hospitals between 2002 and 2006 were screened for the qepA and qnr genes. Two E. coli isolates (0.3%) harbored qepA, but no qnr was identified. The results suggested a low prevalence of E. coli harboring qepA or qnr in Japan.

INTRODUCTION Plasmid-mediated quinolone resistance (PMQR) is a growing clinical concern worldwide. The main aims of this study were to detect qnr-encoding genes and to evaluate the clonal relatedness of qnr-positive Enterobacter cloacae isolates. METHODS A total of 116 E. cloacae isolates that were not susceptible to quinolone were obtained from seven hospitals in Tehran, five hospitals in Qa...