<prompt> Urinary tract infection exists when the bacterial count in 1 ml. midstream specimen of urine is:1001000104105 or over  <response>: Ans. d 105or overRef: Smith 17th Edition, Page 196 105 colony forming unit is used to exclude contamination. 80 of UTI are due to E. Coli. UTI caused by Staphylococcus are due to Hematogenous spread. In Children MC cause - Klebsiella and Enterobacter species. The most reliable Urine specimen is obtained by Supra Pubic Aspiration 