Detection of qnrA gene among quinolone-resistant Escherichia coli isolated from urinary tract infections in Khorram Abad during 2011-2012

Background: Quinolone-resistance in Escherichia coli is ordinarily associated with mutations in the gyrA and parC genes. Plasmid-mediated quinolone resistance (PMQR) was increasingly identified in Enterobacteriaceae family worldwide. The aim of this study was to determine the prevalence of qnrA gene among quinolone-resistant E. coli isolates in Khorram Abad, Iran. Materials and Methods: In this cross-sectional study, one-hundred forty E. coli isolates were collected from urine samples of the patients. Isolates were screened for ciprofloxacin and nalidixic acid resistance using disk diffusion method according to clinical and laboratory standards institute (CLSI) guidelines. Moreover, PCR was used to evaluate the presence of qnrA gene in quinolone-resistant isolates. Results: One-hundred sixteen (82.8) and 63 (43) out of 140 E. coli isolates showed resistance to nalidixic acid and ciprofloxacin, respectively. The results showed that 14 (12.1) nalidixic acid- resistant and 9 (14.3) ciprofloxacin-resistant isolates were positive for qnrA gene. Conclusion: The identification of qnrA gene among quinolone-resistant E. coli isolates shows that the emergence of PMQR in this region requires serious preventive measures