bacteria isolated from urinary tract infection among patients and determination of the antibiotic susceptibility patterns of the gram negative bacteria in iran

background: escherichia coli (e. coli) is the most frequent infecting organism in acute infection. so, knowledge about the frequency and distribution of urinary tract infection (uti) is important to improve infection control measures. the aim of this research was to determine the prevalence of bacteria isolated from urinary tract infection (uti) in patients and determination of the antibiotic susceptibility patterns of the gram negative bacteria. m aterials and methods: this descriptive study was performed in imam reza hospital, tabriz (northwest of iran) during march 2012 to february 2013. we surveyed 8153 patients, who had clinical manifestations of uti. 5093 (62.47%) of them were female and 3060 (37.53%) of them male. urine specimens were cultured for isolation of the microbial agents of uti. the isolated bacteria were identified using biochemical tests. disk diffusion susceptibility test was used to determine antimicrobial susceptibility. r es ults: e. coli (55.38%) was the most common isolated pathogen, followed by enterobacter spp. (29.61%), pseudomonas spp. (4.9%), s. aureus (3.21%), enterococcus spp. (2.3%),  fungi (1.5%) and klebsiell a (0.48%). the sensitivity rates of isolated gram negative bacteria were for amikacin (95.7%), nitrofurantoin (91.5%), gentamicin (64.1%), ceftizoxim (56.8%), ciprofloxacin (37.6%), cotrimoxazole (31.4%) and nalidixic acid (23.5%). c onclusion: this study showed that the frequency of e. coli and   enterobacter spp . increases the probability of urinary tract infection. also this survey indicates the emergence of antibiotic resistant infections in the studied hospital. so, there is a need to improve the effectiveness of integrated infection control programs to control and manage nosocomial infections caused by highly resistant organisms.