Resistance of various pathogens toward quinolones has emerged as a serious threat to combat infections. Analysis of plethora of genes and resistance mechanisms associated with quinolone resistance reveals chromosome-borne and transferable determinants. qnr genes have been found to be responsible for transferable quinolone resistance. In the present work, a new allele qnrVC5 earlier reported in ...

Inappropriate use of antibiotics in clinical settings is thought to have led to the global emergence and spread of multidrug-resistant pathogens. The goal of this study was to investigate the prevalence of genes encoding aminoglycoside resistance and plasmid-mediated quinolone resistance among clinical isolates of Klebsiella pneumoniae. All K. pneumoniae isolates were phenotypically identified ...

Widespread fluoroquinolone resistance has drawn attention to quinazolinediones (diones), fluoroquinolone-like topoisomerase poisons that are unaffected by common quinolone-resistance mutations. To better understand differences between quinolones and diones, we examined their impact on the formation of cleaved complexes (drug-topoisomerase-DNA complexes in which the DNA moiety is broken) with gy...

Sixty extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolated from rivers and lakes in Switzerland were screened for individual strains additionally exhibiting a reduced quinolone susceptibility phenotype. Totally, 42 such isolates were found and further characterized for their molecular (fluoro)quinolone resistance mechanisms. PCR and sequence analysis were performed to identi...

background: emergence klebsiella pneumoniae resistant to quinolone antibiotics due to mutations in gyra and parc genes created problem for treatment of patients in different hospitals in iran. the objective of this study was to determine the amino acid substitutions of gyra and parc proteins in certain clonal lineages of the k. pneumoniae conferring high level quinolone resistance. methods: one...

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...