First detection of plasmid-mediated, quinolone resistance determinants qnrA, qnrB, qnrS and aac(6')-Ib-cr in extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in Budapest, Hungary.

摘要

Quinolone resistance in Enterobacteriaceae usually results from mutations in genes coding for chromosomally encoded type II topoisomerases, efflux pumps or porin-related proteins. Recently, transferable, plasmid-borne, quinolone resistance genes-qnrA, qnrB, qnrS, cr variant of aac(6')-Ib, qepA and oxqB-have been observed in clinical isolates, more frequently among strains producing plasmid-mediated, extended-spectrum [3-lactamases (ESBLs).The objective of this study was to determine the prevalence of qnrA, qnrB, qnrS and aac(6')-Ib-cr genes in ESBL-producing clinical isolates of 70 Escherichia coli, 101 Klebsiella pneumo-niae, 5 Citrobacter freundii and 61 Enterobacter spp., isolated in two microbiological laboratories in Budapest by collecting samples from seven different hospitals and clinics from 2002 until 2006