Although plasmid-mediated quinolone resistance (PMQR) was thought not to exist before its discovery in 1998, the past decade has seen an explosion of research characterizing this phenomenon. The best-described form of PMQR is determined by the qnr group of genes. These genes, likely originating in aquatic organisms, code for pentapeptide repeat proteins. These proteins reduce susceptibility to ...

The aim of this study was to provide a comprehensive analysis of the worldwide genetic polymorphism of ms4760 alleles of the pfnhe-1 gene and to discuss their usefulness as molecular marker of quinine resistance (QNR). A new numbering of ms4760 allele, classification grouping ms4760 alleles according to the number of DNNND and DDNHNDNHNND repeat motifs in blocks II and V was also proposed. A to...

The growing frequency of antibiotic resistances is now a universal problem. Increasing resistance to new generations of β-lactam and quinolone antibiotics in multidrug-resistant Enterobacteriaceae isolates is considered an emergency health issue worldwide. The aim of this study was to evaluate plasmid-mediated quinolone resistance genes in ESBL-producing Escherichia coli isolated from urinary t...

During 1993-2011, cefotaxime resistance among Salmonella enterica isolates from patients in Finland increased substantially. Most of these infections originated in Thailand; many were qnr positive and belonged to S. enterica serovar Typhimurium and S. enterica monophasic serovar 4,[5],12:i:-. Although cefotaxime-resistant salmonellae mainly originate in discrete geographic areas, they represent...

Considering the importance of the mechanisms involved in quinolone resistance, this study evaluate the presence of PMQR in 126 epidemic and not epidemic strains of Salmonella spp. It was noted that presence of PMQR, by itself, did not generate resistance to ciprofloxacin; but detection of qnr genes in Salmonella spp. and the identification of the qnrB19 variant in a strain of poultry origin ale...

Turtle-borne Salmonella enterica owns significance as a leading cause in human salmonellosis. The current study aimed to determine the quinolone susceptibility and the genetic characteristics of 21 strains of S. enterica subsp. enterica isolated from pet turtles. Susceptibility of four antimicrobials including nalidixic acid, ciprofloxacin, ofloxacin, and levofloxacin was examined in disk diffu...

To the Editor: The emergence of plasmid-mediated, and thus transfer-able, quinolone resistance determinants has been recently discovered (1) and shown to involve the pentapeptide repeat protein Qnr, which interacts with DNA gyrase and topoisomerase IV to prevent quinolone inhibition (2,3). Qnr determinants confer resistance to nalidixic acid and reduced susceptibility to fl uoroquinolones (3). ...