Background and purpose: There is a high incidence of urinary tract infection (UTI) and the resistance rate of infectious organisms to antibiotics is increasing. In this study we aimed to investigate the frequency and pattern of antibiotic resistance of pathogens in urinary tract infections in hospitalized patients.

Materials and methods: This cross-sectional study was conducted using 107 urine samples with positive urine cultures form patients with urinary tract infections admitted to the department of infectious diseases in Razi Hospital (an educational hospital in Quemshar), 2011. Then the minimal inhibitory concentration (MIC) of antibiotics was determined by E-Test. Data was analyzed in SPSS (V. 18).

Results: The mean age of the samples was 61.63 ± 18.38 years (age range 10-91 years) and there were 27% male and 73% female. E. coli was found as the most common gram-negative organism (68.2%) that showed a high sensitivity to nitrofurantoin (90.4%) and imipenem (79.5%) and a high resistance against ampicillin (93.2%) and cotrimoxazole (76.7%). Among all infections, the highest antibiotic susceptibility was to nitrofurantoin (81.3%), imipenem (78.5%) and the highest resistance was observed against ampicillin (94.4%).

Conclusion: Antimicrobial therapy should be performed according to the results of urine culture and antimicrobial susceptibility testing.