Association of plasmid-mediated QnrA-like determinant and gene coding for extended-spectrum beta-lactamase VEB-1

Abstract number: 1134_01_58

Mammeri H., Poirel L., Van de Loo M., Nordmann P.


A plasmid mediated QnrA determinant had been identified in Escherichia coli at the Bicetre hospital (France) in 2003. It was associated with a gene coding for the expanded-spectrum beta-lactamase (ESBL) VEB-1. Thus, an investigation was performed for analyzing the prevalence of qnrA-like genes among nalidixic-acid resistant enterobacterial isolates (excluding E. coli) from the same French hospital and in a series of blaVEB-1-positive Gram negative rods.


One hundred thirty nalidixic-acid resistant enterobacterial clinical isolates that were recovered at the Bicetre hospital in 2003 were screened for qnrA-like gene by PCR. A second collection of 92 strains isolated in Thailand during a previous study and including 37 blaVEB-1-positive enterobacterial isolates, 22 blaVEB-1-negative enterobacterial isolates, and 33 blaVEB-1-positive Pseudomonas aeruginosa, was also tested. Mapping and sequencing of the sul1-type integrons were also performed.


Among the nalidixic-acid resistant enterobacterial strains isolated at the Bicetre hospital, a single Enterobacter cloacae that was blaVEB-1-positive harboured a qnrA-like gene whereas eleven blaVEB-1-positive enterobacterial isolates from Thailand were positive. However, qnr-like gene was not identified from the blaVEB-1-negative enterobacterial isolates from Thailand and not from blaVEB-1-positive Pseudomonas aeruginosa isolates. In all isolates, the qnrA-like gene was identical and differed from the original qnrA gene reported by an asparagine to aspartate substitution at position 178 that did not lead to change in the quinolone resistance profile. The qnrA-like genes were located in sul1-type integrons that differed in structure.


This study indicated a further dissemination of Qnr-like determinants among European and South-East Asian isolates and identified a frequent association between this resistance determinant and the gene coding for the ESBL VEB-1.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Location: Oxford, UK
Presentation type:
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