Since quinolones are synthetic antibiotics, it was predicted that mutations in target genes would be the only mechanism through which resistance could be acquired, because there will not be quinolone-resistance genes in nature. Contrary to this prediction, a variety of elements ranging from efflux pumps, target-protecting proteins, and even quinolone-modifying enzymes have been shown to contrib...

background: avian pathogenic escherichia coli (apec), which is the causative agent of colibacillosis, harbors several putative virulence genes. an important trait of apec for both poultry and public health is antibiotic resistance. objectives: in the present study, some potential virulence genes of apecs isolated from northeast of iran and their resistance to the quinolones antibiotics were stu...

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...

background extended-spectrum β-lactamase (esbl) production is the major resistance mechanism to β-lactam antibiotics in enterobacteriaceae. in addition, emergence of plasmid-mediated quinolone resistance (pmqr) in esbl-producing isolates has become a global threat for treatment of these infections. objectives we investigated the association between esbl production and quinolone resistance in ur...

PURPOSE Complications after prostate biopsy have increased and various causes have been reported. Growing evidence of increasing quinolone resistance is of particular concern. In the current retrospective study, we evaluated the incidence of infectious complications after prostate biopsy and identified the risk factors. MATERIALS AND METHODS The study population included 1,195 patients who un...

The quinolone class of antimicrobial agents is one of most widely used classes of antimicrobial agents in outpatient and inpatient treatment. However, quinolone resistance in gram-positive and gram-negative bacteria has emerged and increased globally. This resistance limits the usefulness of quinolones in clinical practice. The review summarizes mechanisms of quinolone resistance and its epidem...

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...

The prevalence of quinolone- and macrolide-resistant Group B Streptococcus (GBS) is increasing worldwide, but the relationship between resistance GBS to these antibiotics patient outcome remains unclear. Therefore, we evaluated whether blood stream infection caused by or associated with high mortality. Our findings in 77 patients bacteremia demonstrate that quinolone macrolide may not be risk f...

Quinolone resistance is caused mainly by chromosomal mutations in gram negative bacteria. In 1998, plasmid-mediated resistance to quinolones in clinical isolates was first reported in a Klebsiella pneumoniae strain. Locus qnr (quinolone resistance) was responsible of the quinolone resistance in this plasmid. qnr codes a protein whose function is protect both DNA-girase and topoisomerase IV from...