The present study aimed to isolate Enterobacteraerogenes from urine of patient with UTI and showing its pathogenicity in mice, a total 150 urine specimens were collected and cultured on MacConky agare then tested biochemically and with API- 20 to confirm diagnosis of Enterobacter aerogenes, after that injected 4 groups of mice with (108,109 and 1010 CFU/ml) respectively, while fourth group consider as a control group, also extracted the cell wall from Enterobacteraerogenes and used four groups of mice to injected with different concentration(300, 200 and 150 μ/ml) of extracted cell wallrespectively, while fourth group consider as a control group. Results shows that 11 isolates of Enterobacter were obtained from urine and out of 11 isolates 8 isolates were belong to Enterobacter aerogenes. Bacterial isolation from internal organs showed very heavy isolation of Bactria in dose 1010 CFU/ml as compared with other dose, histopathological changes of organs for mice injected with live bacteria and extracted cell wall revealed same the tissue damage as compared with control groups.
