author(s)
Dr. Al-wgaa AA and Dr. Alwan MJ

abstract
In order to study the prevalence of Escherichia coli O157:H7, (228) urine samples were collected from young and adult patients from both sexes suffering from Urinary Tract Infection, in addition to collected (75) urine samples from apparently healthy sheep from both genders. The results showed that among (228) human urine samples, 8 (3.50%) samples out of 228 were E.coli O157:H7 positive isolates (6 (5.17%) samples out of (116) in females and 2 (1.7%) samples out of (112) in males). In sheep the results revealed that 13 (17.33%) out of (75) urine samples were E.coli O157:H7 positive isolates. also the current study showed that 11(18.03 %) out of (61) ram's urine samples were positive for E.coli O157:H7 isolates and 2 (14.28 %) out of (14) ewe's urine samples were positive for E.coli O157:H7. The second goal, in these study is determined histopathological lesions in certain internal organs to experimentally infected with E. coli O157:H7. The results reveled that E. coli O 157:H7 cause thrombus, necrosis, apoptosis suppurative inflammation in the examined organs as well as granulomatous reaction in the liver.