Treatment of Recurrent Bacterial Vaginosis Using Engineered Probiotic Bacteria

**Public description**

This project aims to develop new therapies for the prevention of recurrent bacterial vaginosis (BV). Around 30% of women suffer from BV, making it the most common vaginal infection of women of childbearing age. BV is caused by the overgrowth of unwanted bacteria within the vagina. The main problematic bacterium which causes BV is called _Gardnerella vaginalis_. Introduced from sexual contact, the GI tract, or through activities such as vaginal douching, this bacterium colonises the vagina, destroying the healthy, natural bacteria which normally live in the vaginal environment.

All carriers of the _G. vaginalis_ face increased risks of STI transmission, miscarriage (ten-fold increase) and preterm birth (doubled risk). Some BV patients also experience psychologically distressing symptoms (foul-fishy odour/grey white discharge) which can significantly affect mental/sexual health.

The most common BV treatment is the prescription of antibiotics. However, while relieving symptoms temporarily, antibiotics don't prevent BV recurrence. Recurrence usually occurs after a known events which encourage re-growth of _G. vaginalis_: this can include interaction with a new sexual partner or menstruation. 50% of BV patients who have been treated with antibiotics experience BV recurrence within 6 months of therapy. Importantly, antibiotics cannot be used preventatively to treat BV, as this type of usage of antibiotics could lead to the spread of antimicrobial resistance.

In this project, we aim to develop a groundbreaking therapy which would help women to prevent BV before it starts. This therapy will take the form of a probiotic bacterium, to be administered into the vagina by the patient around key trigger events for BV.

To develop this therapeutic, we will select a bacteria which is commonly found in the healthy vagina (Lactobacillus). We will then engineer it, to enable it to "detect" when _G. vaginalis_ is present. We will further modify our therapeutic bacterium so that when it "detects" the presence of _G. vaginalis_, it produces and releases an antimicrobial into the vaginal environment which specifically targets and kills _G. vaginalis_, preventing BV developement. This bacterial probiotic would be the first actively preventative therapy available for women who suffer recurrent/chronic BV, and help fully resolve a distressing condition which is associated with significant negative pre-natal health outcomes.

The research detailed in this project will primarily be conducted by CC Biotech Ltd, in collaboration with academic institutions.

At project conclusion, we will have developed a therapeutic probiotic which is ready for animal safety/efficacy studies/human clinical trials.