Applied Microbiology

Background & Aim: Quinolone resistance has been increasing in recent years. Currently there are three transferable, plasmid-borne quinolone resistance genes, qnr, (qnrA, qnrB, qnrC and qnrS) cr variant of aac(6’)-Ib-cr, qepA. The aim of this study was to investigate the presence of plasmid mediated quinolone resistance genes in E.coli and K. pneumoniae strains isolated from our hospital.

 

Methods: In this study, qnrA, qnrB, qnrS and qnrC and also qepA, aac(6’)-1b-cr plasmid genes were analyzed by molecular methods in quinolone resistant 13 7 E.coli and 15 K. pneumonia isolated in Afyon Kocatepe University hospital. qnrA, qnrB, qnrS and qnrC, qepA were screened by real-time PCR (Rotorgene, Qiagen). The aac(6’)-1b-cr variant was identified by digestion with BseGI restriction enzyme.

 

Results: The prevalence of Extended Spectrum Beta Lactamases (ESBL) production was 52.6% in all isolates (66 E.coli, 14 K. pneumoniae). The qnr genes were detected in three strains. Two strains were positive for qnrB (1 E.coli, 1 K. pneumoniae) while one E.coli strain was positive for qnrS and these strains were producing ESBL. None of the strains had qepA type genes plasmid. aac (6’)-1b-cr plasmid was found 44.7%. Among ESBL producer isolates, this rate was up to 52.5%.

 

Conclusions: In conclusion, the frequency of qnr is reported that to be low in our country, but nonetheless these strains may initiate a rapid increase in bacterial resistance to valuable antimicrobial agents. The prudent use of these antimicrobial agents in clinical practice is necessary to minimize the spread of these resistance genes.