Synonyms: urine culture
Related tests: antibiogram
Clinical significance
Urine culture looks for bacteria in the urine that cause acute and chronic urinary tract infections. The bacteria isolated in culture are identified and tested for susceptibility to the most commonly used antibiotics.
The bacteria most often involved are Enterobacteriaceae, among which Escherichia coli clearly predominates. Monitoring the causes and antibiotic susceptibility of the bacteria responsible for urinary infections in the local area can be of great help to GPs, who often have to start treatment without urine culture results and can then base it on the local epidemiological situation rather than on empirical choice.
Clinical indications
Suspected urinary infection, check after treatment.
Sample type
urine
Preparation
Any antibiotic treatment must be stopped at least 7 days beforehand.
Because urine can pick up bacteria on its way from the bladder through the urethra and the external urethral opening, special collection techniques must be used to ensure a meaningful result. To do this (after washing your hands thoroughly), collect the urine in the morning after washing the area around the urethra, discarding the first stream of urine (midstream technique) and using a sterile container available from pharmacies.
The urine must be delivered to the laboratory within 1 hour.
Notes
A urine culture is considered positive if there are at least 10,000 bacteria (i.e. colony-forming units, or CFU) per ml of urine. In catheterised patients, any count is considered significant.