Culture of urethral discharge; Genital exudate culture; Culture - genital discharge or exudate
Urethral discharge culture is a laboratory test done on men and boys. This test is used to identify germs in the urethra that may be causing urethritis. The urethra is the tube that drains urine from the bladder.
The health care provider uses sterile cotton or gauze to clean the opening of the urethra at the tip of the penis. To collect the sample, a cotton swab is then gently inserted about 3/4 inch (2 centimeters) into the urethra and turned. To get a good sample, the test should be done at least 2 hours after urinating.
The sample is sent to a lab. There, it is placed in a special dish (culture). It is then watched to see if bacteria or any other germs grow.
How to Prepare for the Test
Do NOT urinate for 1 hour before the test. Urinating washes away some of the germs needed for accurate test results.
How the Test will Feel
There is usually some discomfort from swabbing the urethra.
Why the Test is Performed
The provider often orders the test when there is a discharge from the urethra. This test can detect sexually transmitted infections (STIs), such as gonorrhea and chlamydia.
A negative culture, or no growth appearing in the culture, is normal.
What Abnormal Results Mean
Abnormal results can be a sign of infection in the genital tract. These infections can include gonorrhea or chlamydia.
Fainting may occur when the swab is introduced into the urethra. This is due to stimulation of the vagus nerve. Other risks include infection or bleeding.
Augenbraun MH, McCormack WM. Urethritis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 109.
Craft AC, Woods GL. Specimen collection and handling for diagnosis of infectious diseases. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 63.