Detection of Efflux Pumps Genes in Fluoroquinolones Resistant and Sensitive strains of Escherichia coli isolated from Patients with Urinary Tract Infection in Qom

Abstract Background and Objectives: Efflux pumps are one of the main mechanisms for antibiotic resistance in Escherichia coli strains. The aim of this study was to investigate the relationship between 5 different efflux pump genes; acrA, acrB, emrA, emrB and mdtk and fluoroquinolone resistance in E.coli Isolated from patients with urinary tract infections in Qom. Methods: In this descriptive cross-sectional study, clinical samples were collected from several medical centers during June to September 2017. After detection and primary identification of E.coli isolations using culture and biochemical tests, the antimicrobial susceptibility strains to the fluoroquinolones such as Ciprofloxacin, Norfloxacin, Ofloxacin, and Levofloxacin were determined by disk diffusion method according to CLSI guidelines. Identification of the genes encoding efflux pumps was done in sensitive and resistant strains by PCR technique. Result: Of 170 clinical samples, 100 strains of E.coli were isolated and identified based on phenotypic characteristics. Evaluation of antibiotic susceptibility of the strains showed that 63(63%) isolates had resistance to fluoroquinolones. PCR assay demonstrated that the prevalence of acrAB, emrAB and mdtk genes among fluoroquinolones resistant isolates were 100%, 98%, and 94%, respectively, and frequency of the mentioned genes in fluoroquinolone sensitive isolates was 34.2%, 27.02%, and 13.5%, respectively. Conclusion: The results showed that the presence of acrAB, emrAB, and mdtk efflux pumps genes is potentially a factor in resistance to fluoroquinolone antibiotics. The presence of these genes in sensitive strains may indicate that the genes are not transcribed or translated. According to the high resistance of E.coli strains to fluoroquinolone antibiotics, it is recommended that antibiotic susceptibility testing be performed before starting treatment.