Related Experiment Video
Updated: Jun 23, 2026
Detection of Live Escherichia coli O157:H7 Cells by PMA-qPCR
Published on: February 1, 2014
[Real-time PCR for fast detection of plasmid-mediated qnr genes in extended spectrum beta-lactamase producing
T Guillard1, J-D Cavallo, E Cambau
1Laboratoire de bactériologie-virologie-hygiène, CHU Robert-Debré, rue du Général-Koenig, 51092 Reims cedex, France. tguillard@chu-reims.fr
Aim Of The Study:
To develop a fast and reliable real time PCR technique for detecting plasmid-mediated quinolone resistance genes qnrA, qnrB and qnrS.
Methods:
A real-time PCR assay using SYBR Green I and Roche LightCycler(®) was developed to detect qnr genes. Detection of qnr genes was based on comparison of melting temperature differences with a positive control of each qnr genes. This assay was performed to study 138 isolates collected from diagnostic and screening samples in the Champagne-Ardenne region in 2004 (France).
Results:
In optimized conditions, the three positive controls tested alone and with isolates confirmed the specificity of the PCR primers. Each PCR assay was able to test 30 strains in 60min for 1 qnr gene. Out of 138 isolates screened, 3.6 % isolates were positive for a qnrA1, 1.5 % for qnrS1 and no qnrB-like gene. Prevalence of qnr determinants was 5 % and reached 9.5 % in clinical isolates.
Conclusion:
Real-time PCR is a fast and reliable technique for screening of qnr-positive strains. This study shows a relatively high prevalence of qnr determinants (5 %) among ESBL-producing Enterobacteriaceae.
