A urine culture is a lab test to check for bacteria or other germs in a urine sample.
Culture and sensitivity - urine
How the Test is Performed
Most of the time, the sample will be collected as a clean catch urine sample
in your doctor's office or home. You will use a special kit to collect the urine.
A urine sample is taken by inserting a thin rubber tube (catheter) through the urethra into the bladder. This is can be done by a health care provider in the office or at the hospital. The urine drains into a sterile container, and the catheter is removed.
Rarely, the health care provider may choose to collect a urine sample by inserting a needle through the skin of the lower abdomen into the bladder.
The urine is then taken to a lab for testing. Results take 24 - 48 hours.
How to Prepare for the Test
If possible, collect the sample when urine has been in your bladder for 2 to 3 hours.
How the Test will Feel
When the catheter is inserted, you may feel pressure. A special gel is used to numb the urethra.
Why the Test is Performed
Your health care provider may order this test if you have symptoms of a urinary tract infection
or bladder infection, such as pain or burning when urinating.
You may also have a urine culture after you have been treated for an infection. This is to make sure that all of the bacteria are gone.
"Normal growth" is a normal result. This means that there is no infection.
What Abnormal Results Mean
A "positive" or abnormal test is when bacteria or yeast are found in the culture. This most often means that you have a urinary tract infection or a bladder infection.
Other tests may help your health care provider know which bacteria or yeast are causing the infection. The cause of the infection will help determine which antibiotics should be used treat it.
Sometimes more than one type of bacteria, or only a small amount may be found in the culture.
There is a very rare risk of a hole (perforation) in the urethra or bladder if your doctor or nurse uses a catheter.
You may have a false-negative urine culture if you have been taking antibiotics.
Hooton TM, Bradley SF, Cardenas DD, et al. Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 International Clinical Practice Guidelines from the Infectious Diseases Society of America. Clin Infect Dis. 2010;50(5):625-663.
Ban KM, Easter JS. Selected urologic problems. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, PA: Mosby Elsevier; 2009:chap 97.
Dean AJ, Lee DC. Bedside laboratory and microbiologic procedures. In: Roberts JR, Hedges JR, eds. Clinical Procedures in Emergency Medicine. 5th ed. Philadelphia, PA: Saunders Elsevier; 2009:chap 68.
Daniel Levy, MD, PhD, Infectious Diseases, Lutherville Personal Physicians, Lutherville, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.