• Antibiotic resistance pattern of E. coli isolated from urinary tract infections in Al-Zahra hospital of Rasht
  • Shayan Imani,1,* Mohammad Ghadimi,2
    1. Department of Microbiology, Islamic Azad University of Sanandaj Branch, Sanandaj, Iran
    2. Department of Microbiology of Al-Zahra Hospital of Rasht, Rasht, Iran


  • Introduction: Urinary tract infections (UTI) are among the most common infectious diseases that annually involve millions of people around the world. UTIs occur in both sexes in any ages but it is more common in females. Gram-negative bacteria such as Escherichia coli strains are one of the most important causative agents of these infections. A variety of antibiotics are used to treat such infections but evidences show that the excessive and unnecessary use of antibiotics to treat these infections leads to increase of antibiotic resistance among bacteria. The current study was performed to determine the antibiotic resistance model and susceptibility of E. coli strains that were isolated from urine cultures of patients admitted to Al-Zahra hospital in Rasht.
  • Methods: In this descriptive-analytical study, 4632 urine samples were evaluated during a 12-month period, from June 2017 to June 2018. Urine samples were cultured on both EMB and blood agar plates then the positive cultures were evaluated to identify the infection agents. The antibiotic resistance pattern to nine different antimicrobial agents for all isolates was determined by disk diffusion method as recommended by Clinical and Laboratory Standards Institute (CLSI) method. The resulted data was arranged using Standard statistical methods. Only the specimens demonstrating E. coli growth in the culture were included in the analysis for this study.
  • Results: 832 samples were reported as positive cultures that 206 cases of them came out positive for E. coli. According to antibiogram results, the highest antibiotic resistance of E. coli isolates in respect were reported for Nalidixic acid (50%), Trimethoprim/sulfamethoxazole (47.59%), Cephalexin (44.96%) and Cefotaxim (31.1%). Furthermore the highest sensitivity rates were related to Nitrofurantoin (94.61%), Amikasin (90.64%), Gentamicin (78.72%), Imipenem (76.74%) and Ciprofloxacin (74.56%), respectively.
  • Conclusion: According to the results, the highest sensitivity of the isolated E. coli strains was to Nitrofurantoin and Amikacin also the highest antimicrobial resistance belonged to Nalidixic acid. Therefore, Nitrofurantoin and Amikacin can be proposed to treat urinary tract infections with E. coli while Nalidixic acid is not appropriate in most patients with UTI.
  • Keywords: Antibiotic resistance, urinary tract infections, E. coli, antibiogram