200 urine samples were collected from patients expected to have urinary tract infection, 123 samples gave positive bacterial growth in culture. From positive cultures, (41) bacterial samples were identified as E.coli (33.3%). Percentage of E.coli in samples taken from females was 66% while 34% of E.coli isolates were identified in male samples.Sensitivity tests toward 14 antibiotics were carried out , results showed that ciprofloxacin, amikacin, and Naldixic acid were the most effective antibiotics and their resistance percentage were 5%, 5%, and 9.8% respectively. While ampicillin, cephalexin, and erythromycin were not effective and their resistance percentage were 100%.Six isolates namely, no.5, 16, 30, 31, 35, and 41 were selected depending on the result of antibiotic sensitivity , and tested for adherence ability to uroepithelial cells from normal females. All tested isolates were found to adhere to uroepithelial cells . however , isolate no 5 showed the highest ability of adherence with the mean no. of adhering bacteria equivalent to 34 bacteria per uroepithelial cell .Plasmid profiles of the six selected isolates were investigated by gel electrophoresis. The isolates no. 16, 30, 31, 35 showed several small bands(1-3 bands) in addition to large one ( probably mega plasmid), however isolates no. 5, 41 have no plasmids.Curing experiments were carried out by treating the isolates no. 16, 30, 31, 35 with Acridine Orange to study the possible role of plasmids of E.coli in adherence ability.The obtained results showed that isolates no. 16, 30, and 35 lost their antibiotic resistance determinants of Cotrimoxazole, Gentamicin, Naldixic acid, Tetracycline, and Ciprofloxacin, indicating that resistance to these antibiotics is under plasmid control, whereas Ampicillin, Cephalexin, Erythromycin, and Cefotaxime resistant determinants were not affected .Adherence experiment showed that the ability of plasmid cured isolates for adherence to uroepithelial cell were not affected.
