Paper Title
The Phenotypic and Molecular Survey Inciprofloxacin–Resistant Escherichia Coli Isolates Fromurinary Tract Infections (UTIS)

Abstract
Background: Escherichia coli (E. coli)is the most frequent pathogen of UTIs. Ciprofloxacin is efficient in persistent and recurrent UTIs, but the increasing chromosomal or plasmid resistancein the bacteria has become a major health problem. The aim of this study was phenotypic and molecular survey in ciprofloxacin–resistant Escherichia coli isolates from urinary tract infections (UTIs). Methods: E. coli isolatesof midstream urine samples of 124 UTI patients who referred to Imam Khomeini and Sina hospitals of Tehran during May-October 2014 were collected. All isolates were subjected to antimicrobial susceptibility testing (AST) by standard disk diffusion method and Minimal inhibitory concentration (MIC) of ciprofloxacin was determined by E-test stripsaccording to CLSI2017protocols. The role ofchromosomal genes, par EC, gyrA and plasmidqnrAB genes were determined after DNA extraction and using PCR. Further sequencing and gene submissionin NCBI gene bank was done. Results: 64.5% of UTIs were positive for E. coli. Based on AST77.5% of isolates were resistant to ciprofloxacin.All isolates with MIC ≥4μg/mL for ciprofloxacin were the candidate for DNA extraction, PCR and further sequencing.The gyrA,parC, parE,qnrA and qnrB genes, were detected in 100%,90.9%, 97.67%, 39% and 0% of isolates, respectively. During sequence analysis, some mutation was seen ingyrA gene and different mutations in parE gene were detected.Further submission of parCandparE and gyrAgenesin NCBI GenBank was performed with accession numbers,KT454384.1, KT454385.1 and KX587467.1, respectively. Conclusion: contribution of both mutated chromosomal genes and plasmidicqnrA resistance genes in some of the high ciprofloxacin resistant bacterial isolates in this study besides the overuse of antibiotics, can increase the emergence of resistant strains.