conclusions the most common qnr gene was qnrb, and none of the isolates carried qnra or qepa. the aac (6’)-ib-cr variant was the most prevalent pmqr gene, and it was associated with the prevalence of ciprofloxacin resistance in our esbl-producing isolates. results of the 123 isolates, 103 (83.73%) had one of the five pmqr genes, including 83 (83.83%) of the 99 e. coli strains and 20 (86.95%) of...

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...

Abstract Background Emergence of fluoroquinolone resistance in gut pathogens is a cause concern. Resistant to quinolone mainly due the point mutations at quinolone-resistance determining regions (QRDR). The aim study was develop polymerase chain reaction-restriction fragment length polymorphism assay (PCR-RFLP) detect QRDR gyrA and gyrB enteric pathogens. Methodology PCR-RFLP done for 83 region...

Objective: Although quinolone resistance results mostly from chromosomal mutations in Klebsiella pneumoniae, it may also be mediated by plasmid – encoded qnr determinants. Plasmid-mediated quinolone resistance (PMQR) was increasingly identified in Enterobacteriaceae family worldwide. The aim of this study was to investigate the prevalence of qnr genes in clinical isolates of Klebsiella pn...

In the title mol-ecule, C(16)H(9)NO(5)S, there is an intra-molecular O-H⋯O hydrogen bond involving the quinolone carbonyl O atom and a carboxyl OH group. In the crystal, inter-molecular O-H⋯O hydrogen bonds between the carbonyl group of the quinolone carboxyl group, and a second carboxyl group on the thia-zeto moiety lead to the formation of chains propagating along [201] and perpendicular to t...

Until recently, Salmonella enterica serotype Enteritidis has remained sensitive to most antibiotics. However, national surveillance data from Denmark show that quinolone resistance in S. Enteritidis has increased from 0.8% in 1995 to 8.5% in 2000. These data support concerns that the current use of quinolone in food animals leads to increasing resistance in S. Enteritidis and that action should...

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...

We synthesized a range of PQS (Pseudomonas quinolone signal; 2-heptyl-3-hydroxy-4(1H)-quinolone) analogues and tested them for their ability to stimulate MvfR-dependent pqsA transcription, MvfR-independent pyoverdine production, and membrane vesicle production. The structure-activity profile of the PQS analogues was different for each of these phenotypes. Certain inactive PQS analogues were als...

Analysis of 71 ciprofloxacin-resistant (MIC > or = 4 microg/ml) Streptococcus pneumoniae clinical isolates revealed only 1 for which the quinolone resistance-determining regions of the parC, parE, and gyrB genes were genetically related to those of viridans group streptococci. Our findings support the occurrence of interspecies recombination of type II topoisomerase genes; however, its contribu...