Molecular Characterization of Ciprofloxacin- Resistance in uropathogenicEscherichia coli Strains isolated from Children

Background and purpose: Bacterial urinary tract infection is among the most commondiseases in childhood. Its treatment is difficult due to the increasing prevalence of resistantstrains. Quinolones are a large group of synthetic drugs, among which ciprofloxacin is one ofthe most common antibiotics effective on Gram-negative bacteria, especially Escherichiacoli. In E. coli, the main purpose of quinolone is DNA gyrase which is encoded by gyrA andgyrB genes. Mutations in the QRDR section of gyrA genes are one of the most commonreasons for resistance of such bacteria to quinolone. The aim of this study was to study theantibiotic resistance of one of the leading quinolones used in treatment of urinary tractinfections in children and the model of genes involved in it.Materials and Methods: In this study, urine samples of ۸۳ children with symptoms ofurinary tract infection were tested, and biochemical and bacteriological tests were carried outto isolate and identify E. coli. The drug resistance pattern of isolates to ciprofloxacin wasdetermined using disk diffusion and Broth Microdilution methods. Strains resistant tociprofloxacin were placed under the PCR to study their mutation point.Results: In this study, ۶۰ isolates were identified and separated as E. coli, out of which۲۱.۷% were resistant to ciprofloxacin. After PCR was completed on isolates resistant tociprofloxacin, it was revealed that mutation had taken place in the serine ۸۳ of gyrA gene.Conclusions: The results of this study indicate the growing resistance of pathogenic E. coliurinary tract infection to the selective antibiotics used to treat it. Mutations in these strainsalso play an important role in the creation of such antibiotic resistance.

Keywords:

Escherichia coli , ciprofloxacin , Children , Urethritis , gyrA