Antibiotic Resistance Pattern against Fluoroquinolones among Escherichia coli Isolated from ICU and Out- patient Clinic Admitted Patients with Urinary Tract Infection

Widespread use of fluoroquinolones has resulted in an increasing incidence of resistance to these agents. Therefore antibiotic resistance surveillance has a great importance. This study was carried out to evaluate the antibiotic resistant pattern of Escherichia coli isolates against fluoroquinolones from ICU and out- patient clinic admitted patients with urinary tract infection in Imam Hospital of Tabriz. Urine samples were taken and E. coli were isolated by conventional laboratory methods. The isolated strains were testes by Disk Agar Diffusion (DAD) method and broth macro-dilution method (MIC) according to the CLSI guidelines. A total of hundred E. coli were isolated from urine samples. According to the results of DAD method 57 (57%) were resistant to nalidixic acid, 34 (34%) to norfoloxacin, 33 (33%) to ciprofloxacin and 30 (30%) to ofloxacin. Also 2 (2%) of isolates revealed intermediate resistance to ofloxacin. By broth macro-dilution 41% were resistant to ciprofloxacin (MIC ≥ 4µg/ml), while 6 isolates had intermediate resistance pattern (MIC=2 µg/ml) and 53 isolates were sensitive (MIC≤ 1 µg/ml) to ciprofloxacin. Our results revealed a high level of resistance against fluoroquinolones. It would be because of unjustified antibiotic usage. To overcome this problem inadvertent prescription should be limited and antibiotics should be administered based of microorganism sensitivity patterns.