New insights into bacteria may prevent vaginal infections
Several different bacteria play a role in the onset and development of bacterial vaginosis, a bacterial infection of the vagina. This is according to research by Celia Segui-Perez, Karin Strijbis and colleagues, published this week in the journal mBio. The researchers showed that a bacterium about which little was known until now contributes to bacterial vaginosis. They also found a method to prevent harmful effects of this bacterium on the vaginal wall.
Bacterial vaginosis is common, estimated to affect 10 to 50 per cent of women in the Netherlands. It causes symptoms such as itching, pain and altered discharge and can lead to reduced fertility, premature birth and an increased risk of sexually transmitted diseases such as HPV and HIV. Risk factors for getting bacterial vaginosis include antibiotic use, wearing an IUD, washing with soap, regular sexual contact and reduced immunity. Despite the scale of the problem, there is relatively little research into this condition and the causes of it.
Investigating harmful bacteria
Bacterial vaginosis involves the presence of many harmful bacteria that attach to the vaginal wall and break down its protective layer. The harmful bacteria replace the bacteria that, in a healthy vagina, regulate acidity and keep the vaginal wall healthy. The most well-known bacterium contributing to vaginosis is Gardnerella vaginalis. Relatively little was known about other harmful bacteria, even though they are present in a large proportion of patients with vaginosis.
The research by Strijbis and colleagues shows how important it is to study these other bacteria as well. “In our study, we looked at the unique properties of the bacterium Prevotella timonensis. We found that this bacterium can adhere well to the vaginal wall and break down the protective mucus layer, suggesting that it may play an important role in the development of bacterial vaginosis.”
Prevention and cure
The breakdown of the protective layer is caused by enzymes (sialidases) that cut off sugars from this layer. The activity of these enzymes is a hallmark of bacterial vaginosis and is used in diagnosing patients. The researchers found that the bacterium Prevotella timonensis secretes these enzymes. “In collaboration with a group at Harvard, we found that one specific enzyme from Prevotella timonensis is common in women with vaginosis”, Strijbis says.
The study offers hope for future treatment of patients with vaginosis. Strijbis: “We have shown that we can deactivate this enzyme so that it no longer causes damage to the vaginal wall. In the future, we want to develop this technique further to eventually use it in the clinic to prevent and cure bacterial vaginosis.”