Gram stain of urethral discharge

• Alternative Names

  Urethral discharge gram stain

• How the test is performed

  Fluid from the urethra is collected on a cotton swab. A sample from this swab is applied in a very thin layer to a microscope slide. A series of stains called a gram stain is applied to the specimen.

  The stained smear is then examined under the microscope for the presence of bacteria. The color, size, and shape of the cells help identify the organism causing the infection.

• How to prepare for the test

  This test is often performed in the health care provider's office.

• How the test will feel

  You may feel pressure or burning when the cotton swab touches the urethra.

• Why the test is performed

  The test is performed when an abnormal urethral discharge is present. It may be performed if a sexually transmitted disease is suspected.

• Normal Values

  No presence of organisms is normal.

• What abnormal results mean

  Abnormal results may indicate gonorrhea or other infections.

• What the risks are

  There are no risks.

• Special considerations

  A culture of the specimen (urethral discharge culture) should be performed in addition to the gram stain. More sophisticated diagnostic tests (such as PCR tests) are sometimes also done.

• References

  Workowski KA, Berman SM. Diseases characterized by urethritis and cervicitis. Sexually transmitted diseases treatment guidelines 2006. Centers for Disease Control and Prevention. MMWR. 2006 Aug 4;55(RR-11):35-49.

  Centers for Disease Control and Prevention (CDC). Update to CDC's sexually transmitted diseases treatment guidelines, 2006: fluoroquinolones no longer recommended for treatment of gonococcal infections. MMWR.2007 Apr 13;56(14):332-6.

Review Date: 8/9/2009

Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.