Definition This is a test of a sample of urine to see if there are infection-causing organisms present. If there are, the organisms are identified so that the doctor can prescribe a program of antibiotics or other therapy.
Who is a candidate for the test? Doctors perform this test on people whom they suspect have either a problem with urinary retention or a urinary tract infection.
How is the test performed? There are two methods for collecting urine: the clean-catch method and the catheterisation method.
The mid stream method: First, the person washes around the urethra, the tube that passes urine out of the body. This prevents contamination of the sample. Next, the person needs to collect a urine sample in midstream, that is, not at the beginning and not at the end. In other words, an individual starts to urinate into the toilet, stops and voids some of the urine into a container, then finishes by urinating into the toilet. The individual then covers the container and gives it to the doctor. The sample is sent to a laboratory for testing.
Catheterisation method: Doctors use this method when the person has difficulty urinating. First, the area around the urethra is washed to prevent contamination. Then, the doctor passes a sterile, lubricated catheter, which is a thin, flexible tube, through the urethra and into the bladder. The urine flows into a sterile container. The doctor removes the catheter when the sample has been collected. The sample is taken to the laboratory.
In the laboratory, the urine sample is grown on culture media. If any disease-causing microorganisms grow on the culture plate, these are identified. This allows the doctor to choose a treatment program.
What is involved in preparation for the test? People may ask their doctors how to prepare for the test.
What do the test results mean? Normally, no microorganisms grow on the culture media. If microorganisms do grow, the test is positive. That may indicate a urinary tract infection.
Author: David T. Moran, MD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 26/05/2005 Contributors Potential conflict of interest information for reviewers available on request