Urine culture
Definition
A urine culture is a lab test to check for bacteria or other germs in a urine sample.
It can be used to check for a urinary tract infection in adults and children.
Alternative Names
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 health care provider's office or your home. You will use a special kit to collect the urine.
A urine sample can also be taken by inserting a thin rubber tube (catheter) through the urethra into the bladder. This is done by someone in your provider's office or at the hospital. The urine drains into a sterile container, and the catheter is removed.
Rarely, your provider may collect a urine sample by inserting a needle through the skin of your lower abdomen into your bladder.
The urine is taken to a lab to determine which, if any, bacteria or yeast are present in the urine. This takes 24 to 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 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 also may 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 Results
"Normal growth" is a normal result. This means that there is no infection.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.
What Abnormal Results Mean
A "positive" or abnormal test is when bacteria or yeast are found in the culture. This likely means that you have a urinary tract infection or bladder infection.
Other tests may help your provider know which bacteria or yeast are causing the infection and which antibiotics will best treat it, if treatment is needed.
Sometimes more than one type of bacteria, or only a small amount, may be found in the culture.
Risks
There is a very rare risk for a hole (perforation) in the urethra or bladder if your provider uses a catheter.
Considerations
You may have a false-negative urine culture if you have been taking antibiotics.
References
Cooper KL, Badalato GM, Rutman MP. Infections of the urinary tract. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 55.
Nicolle LE, Drekonja D. Approach to the patient with urinary tract infections. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 268.
Review Date:10/20/2022
Reviewed By:Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.
Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.