Gardnerella vaginalis is one of a number of bacteria including Mycoplasma hominis and several anaerobic organisms that cause the bacterial vaginosis syndrome characterized by a fishy smelling and white vaginal discharge, according to "Harrison's Principles of Internal Medicine." Among women of childbearing age, bacterial vaginosis most commonly causes vaginal infection, according to the Centers for Disease Control.
Change in Flora
The major commensal organism in the vagina of a normal premenopausal woman is Lactobacillus sp; this bacterium produces lactic acid and hydrogen peroxide and maintains an acidic vaginal pH that provides a natural defense against the growth of unhealthy bacteria.
A number of factors can decrease Lactobacillus sp. in the vagina and replace it with high concentrations of anaerobic bacteria, such as Prevotella sp. and Mobiluncus sp. They include douching, spermicides containing 5 or 12 percent nonoxynol-9, new sex partners and broad-spectrum antibiotics. Bacterial vaginosis results from this change from healthy Lactobacillus sp. to unhealthy anaerobic bacteria, including Gardnerella vaginalis residing in the vaginal ecosystem. This disturbed bacterial flora raises the pH of vaginal fluid.
Pregnancy
In the journal Maternal-Fetal Investigation, Dr. Jong-Chou Chang says that bacterial vaginosis develops in approximately 15 to 20 percent of pregnant women in the United States. Bacterial vaginosis during pregnancy can cause post-cesarean endometritis, premature rupture of membranes and preterm labor and delivery.
Sexual Activity
"Harrison's Principles of Internal Medicine" says an increased risk of developing bacterial vaginosis occurs in women who have a newly diagnosed human papillomavirus genital infection, which is a sexually transmitted disease, or have multiple sexual partners. Women who have never been sexually active are rarely affected.
References
- "Harrison's Principles of Internal Medicine"; Dennis Kasper, M.D.; 2005
- CDC STD Treatment: Bacterial Vaginosis
- CDC Fact Sheet: Bacterial Vaginosis
- "Journal of Maternal-Fetal Investigation": Vaginal and Cervical pH Measurements in Normal Pregnancy and Preterm Labor; Jong-Chou Chang; Dec 1997; Vol 7 (4); 193-6
