INTRODUCTION At the time of the study, 3 plasmid-borne qnr determinants (qnrA, qnrB and qnrS) and 1 plasmid-borne aminoglycoside-modifying enzyme determinant that confers quinolone resistance (aac(6')-Ib-cr) had been described in the literature. MATERIALS AND METHODS We studied the prevalence of the 3 qnr determinants in a total of 117 nalidixic acid-resistant urinary isolates of Klebsiella p...

The prevalence of three plasmid-mediated quinolone resistance determinants, QnrA, QnrB, and QnrS, among 526 nonreplicate clinical isolates of Enterobacter cloacae collected at a Taiwanese university hospital in 2004 was determined by PCR and colony hybridization, and the association of Qnr with the IMP-8 metallo-beta-lactamase was investigated. Eighty-six (16.3%) of all isolates were qnr positi...

background: acute infectious diarrhea is one of the most important causes of morbidity and mortality worldwide. objectives: the objective of this study was to characterize antimicrobial resistant diarrheagenic escherichia coli strains isolated from diarrheic children in tehran, ir iran. patients and methods: in total, 550 stool samples from diarrheic pediatric patients, aged less than 60 months...

Quinolones inhibit bacterial type II DNA topoisomerases (e.g. DNA gyrase) and are among the most important antibiotics in current use. However, their efficacy is now being threatened by various plasmid-mediated resistance determinants. Of these, the pentapeptide repeat-containing (PRP) Qnr proteins are believed to act as DNA mimics and are particularly prevalent in gram-negative bacteria. Predi...

High levels of pharmaceuticals, including fluoroquinolones (FQs), have been detected in the effluent from an Indian waste water treatment plant serving bulk drug production intended for the global market. Responses from short-term effluent exposure were studied in fish and rats through explorative analyses of hepatic mRNA abundance, enzyme activities and blood chemistry parameters. Exposure of ...

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.

A total of 232 isolates of gram-negative bacteria were recovered from mammals, reptiles, and birds housed at Asa Zoological Park, Hiroshima prefecture, Japan. Forty-nine isolates (21.1%) showed multidrug resistance phenotypes and harbored at least one antimicrobial resistance gene. PCR and DNA sequencing identified class 1 and class 2 integrons and many beta-lactamase-encoding genes, in additio...

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-fermenters are aerobic non-spore forming Gram-negative bacilli that either incapable of catabolized carbohydrates as a source of energy or degrade them via oxidative rather than fermentative metabolic pathways. In the group of non-fermenters Pseudomonas aeruginosa is eminent pathogen followed by Acinetobacter baumanni. Both of these organisms are reported for their intrinsic resistance agai...