Seventeen qnr-containing transconjugants were constructed with azide-resistant Escherichia coli J53 as the recipient, and the MICs of 12 quinolones were tested by agar dilution methods. Sitafloxacin, BAYy3118, and premafloxacin had higher activity in vitro than ciprofloxacin against transconjugants and donors containing qnr. The donors had higher quinolone MICs than the transconjugants.

Antimicrobial consumption is one of the major contributing factors facilitating the development and maintenance of bacteria exhibiting antimicrobial resistance. Plasmid-mediated quinolone resistance (PMQR) genes, such as the qnr family, can be horizontally transferred and contribute to reduced susceptibility to fluoroquinolones. We performed an observational study, investigating the copy number...

Non-typhoidal salmonellosis is an important zoonotic disease caused by Salmonella enterica. The aim of this study was to investigate the prevalence of plasmid-mediated quinolone resistance in Salmonella spp. and its association with fluoroquinolone susceptibility in Brazil. A total of 129 NTS isolates (samples from human origin, food from animal origin, environmental, and animal) grouped as fro...

OBJECTIVES To detect the qnrA, qnrB and qnrS genes among Salmonella isolates received at the French National Reference Centre for Salmonella in Paris, France. METHODS Antibiotic susceptibility was determined by disc diffusion for 499 Salmonella isolates including 320 Salmonella Typhimurium, 100 Salmonella Enteritidis and 79 Salmonella Hadar collected in 2002. Amplification with specific prime...

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...

Quinolone resistance encoded by the qnr gene and mediated by plasmid pMG252 was discovered in a clinical strain of Klebsiella pneumoniae that was isolated in 1994 at the University of Alabama at Birmingham Medical Center. The gene codes for a protein that protects DNA gyrase from quinolone inhibition and that belongs to the pentapeptide repeat family of proteins. The prevalence of the gene has ...

Abstract Background This study was aimed to determine the prevalence of qnr genes among fluoroquinolone-resistant Escherichia coli (FREC) isolates from Nigeria. Antimicrobial susceptibility testing performed by disc diffusion technique. Polymerase chain reaction used identify ( E. ) and for detection genes. Results A total 206 non-duplicate were isolated 300 clinical specimens analyzed. In all,...

Antibiotic resistance is now a linked global problem. Dispersion of successful clones of multidrug resistant (MDR) bacteria is common, often via the movement of people. Local evolution of MDR bacteria is also important under the pressure of excessive antibiotic use, with horizontal gene transfer providing the means by which genes such as bla(CTX-M) spread amongst different bacterial species and...

Cajal-Retzius (CR) cells are early-generated transient neurons and are important in the regulation of cortical neuronal migration and cortical laminar formation. Molecular entities characterizing the CR cell identity, however, remain largely elusive. We purified mouse cortical CR cells expressing GFP to homogeneity by fluorescence-activated cell sorting and examined a genome-wide expression pro...