Endocervical gram stain
Endocervical gram stain is a method of identifying bacteria on tissue from the cervix using a special series of stains.
Gram stain of cervix
How the test is performed
The health care provider will obtain a tissue sample from the lining of the cervical canal (the opening to the uterus).
You lie on your back with your feet in stirrups. As in a regular pelvic examination, a speculum (an instrument used to stretch open the vagina in order to better examine some of the pelvic organs) will be inserted and opened slightly.
The cervix is cleaned so there is no mucus. A dry, sterile swab is then inserted and rotated in the cervical canal. It may be left in place for several seconds to absorb as many of the organisms as possible.
The swab is then removed and sent to a laboratory, where it will be smeared on a slide. A series of stains called a gram stain is applied to the specimen.
A laboratory technician examines the stained smear under the microscope for the presence of bacteria. The color, size, and shape of the cells help identify the type of bacteria.
How to prepare for the test
Do not douche for 24 hours before the procedure.
How the test will feel
You may feel minor discomfort during specimen collection. This procedure feels very much like a routine Pap smear.
Why the test is performed
The test is used to detect and identify abnormal bacteria in the area of the cervix. If you develop signs of an infection or suspect that you have a sexually transmitted disease (such as gonorrhea), this test can help confirm the diagnosis, and identify the organism that is causing the infection.
There are no abnormal bacteria present. Note that the normal cervix has "friendly" bacteria that the gram stain will pick up.
What abnormal results mean
- Bacterial vaginosis
- Yeast infection
The test may also be performed for gonococcal arthritis, to determine the site of the initial infection.
What the risks are
There is virtually no risk.
If you have gonorrhea or another sexually transmitted infection, it is very important that all of your sexual partners also receive treatment, even if they have no symptoms.
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.
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.