conclusions the high prevalence of quinolone resistance genes, which indicates antibiotic resistance, in the imam reza hospital of mashhad is a major concern. hence, the antibiotics prescription policy should be revised, and infection control measures should be improved. results eighty-six (43%) isolates were ciprofloxacin-resistant. the pct identified 85 (42.5%) of 200 e. coli isolates as esbl...

BACKGROUND Quinolone resistance in Enterobacteriaceae species has increased over the past few years, and is significantly associated to beta-lactam resistance. The aim of this study was to evaluate the prevalence of chromosomal- and plasmid-mediated quinolone resistance in acquired AmpC β-lactamase and/or carbapenemase-producing Enterobacteriaceae isolates. METHODS The presence of chromosomal...

OBJECTIVES The aim of this study is to evaluate the prevalence and diversity of extended-spectrum beta-lactamases (ESBLs) in Enterobacter cloacae clinical isolates collected from Algerian hospitals and to verify the association with qnr genes. METHODS MICs were determined by Etest for isolates giving positive double-disc synergy tests, and all isolates were screened by PCR and sequenced, resp...

The objective of this study was to identify mutations in the Quinolone Resistance Determining sources Regions (QRDR) of the gyrA, gyrB, parC, and parE genes and to determine if any of the qnr variants or the aac(6')-Ib-cr variant were present in strains of Salmonella spp. isolated in Brazil. A total of 126 Salmonella spp. strains from epidemic (n = 114) and poultry (n = 12) origin were evaluate...

OBJECTIVES Escherichia coli is regarded as the most important etiological agent of urinary tract infections. Fluoroquinolones are routinely used in the treatment of these infections; however, in recent years, a growing rate of resistance to these drugs has been reported globally. The aims of this study were to detect plasmid-mediated qnrA, qnrB, and qnrS genes among the quinolone-nonsusceptible...

In this study, we investigated the presence of plasmid-mediated quinolone resistance (PMQR) genes among 101 ciprofloxacin-resistant urinary Escherichia coli isolates and searched for mutations in the quinolone-resistance-determining regions (QRDRs) of the DNA gyrase and topoisomerase IV genes in PMQR-carrying isolates. Eight isolates harboured the qnr and aac(6')-Ib-cr genes (3 qnrS1, 1 qnrB19 ...

Resistance to quinolones and fluoroquinolones is being increasingly reported among human but also veterinary isolates during the last two to three decades, very likely as a consequence of the large clinical usage of those antibiotics. Even if the principle mechanisms of resistance to quinolones are chromosome-encoded, due to modifications of molecular targets (DNA gyrase and topoisomerase IV), ...

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...

Fluoroquinolones are poorly active against enterococci. Recently, plasmid-borne resistance to fluoroquinolones due to the qnr gene was reported in members of the Enterobacteriaceae family. The gene encodes a pentapeptide repeat protein that protects DNA gyrase from inhibition by fluoroquinolones. We have identified in the genome of Enterococcus faecalis V583 a qnr-like gene, named E. faecalis q...