Week 9 – Review Sheet Exercise 5 - Urine Culture Techniques What is bacteriuria? When is it significant? How do microorganisms enter the urinary tract? Why is aseptic urine collection important when cultures are ordered? List five bacteria that can cause urinary tract infection. If you counted 20 colonies from a 0.01-ml inoculum of a 1:10 dilution of urine, how many organisms per milliliter of specimen would you report? Is this number significant?