This work describes the characterization of plasmid-mediated quinolone-resistance (PMQR) genes from a multicenter study of ESBL-producing Enterobacteriaceae pediatric clinical isolates in Mexico. The PMQR gene-positive isolates were characterized with respect to ESBLs, and mutations in the GyrA and ParC proteins were determined. The phylogenetic relationship was established by PFGE and the tran...

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...

Alanine substitution mutations in the Cry1Ac domain III region, from amino acid residues 503 to 525, were constructed to study the functional role of domain III in the toxicity and receptor binding of the protein to Lymantria dispar, Manduca sexta, and Heliothis virescens. Five sets of alanine block mutants were generated at the residues (503)SS(504), (506)NNI(508), (509)QNR(511), (522)ST(523),...

Nontyphoidal Salmonella enterica strains with a nonclassical quinolone resistance phenotype were isolated from patients returning from Thailand or Malaysia to Finland. A total of 10 isolates of seven serovars were studied in detail, all of which had reduced susceptibility (MIC > or = 0.125 microg/ml) to ciprofloxacin but were either susceptible or showed only low-level resistance (MIC < or = 32...

OBJECTIVES The aim of this study was to determine the prevalence and characteristics of qnr-carrying Salmonella isolates from humans in southern Taiwan. METHODS A total of 446 Salmonella isolates collected between 2003 and 2006 were screened for qnrA, qnrB and qnrS by PCR experiments. Genetic structures of qnr were determined by PCR-based methods or direct sequencing of plasmid DNA. RESULTS...

Aeromonas spp. are oxidase positive, gram-negative, facultative anaerobic bacilli that are widely distributed in aquatic environments. A.hydrophila, A.sobria and A.bestiarum may cause severe infections in both human and cold-blooded animals. Environmental persistance of quinolones that are widely used in both human and veterinary medicine plays an important role in the selection of resistant mu...

conclusions ctx-m was the most prevalent esbl genotype in uropathogenic e. coli (upec) isolated from uti. in addition, a high frequency of qnr genes among esbl-producing e. coli was identified in this study. in order to avoid treatment failures, we recommend using phenotypic and molecular methods to diagnose these enzymes and qnr genes. results the highest sensitivity was seen to imipenem (96.7...