In the media, we are used to seeing TV adverts of people in developing countries being forced to choose between drinking unsanitary water or dehydration. These adverts often contain a message along the lines of 'every drop could kill'; what is it precisely that's making this water so dangerous? Disease-causing bacteria. And that's where we decided to come in:

We chose to focus on the diseases cholera and Shigellosis - two of the main culprits contributing to unclean drinking water related fatalities - due to the sheer scale of deaths they cause per year and as neither has an affordable, readily available cure for affected people in developing countries. Their respective bacteria (Vibrio cholerae for Cholera, Shigella for Shigellosis) are also similar both to each other and to the bacterium we chose as a model, E. coli, meaning they were a perfect fit for our project.

Ultimately, our final product developed into what is mainly a preventative method; it stops Vibrio cholerae and Shigella from becoming virulent, and so renders them harmless.

We have achieved this by utilising the natural process of RNA interference (RNAi). For this, we have designed, constructed and/or characterised a number of different basic and composite parts which would work together to effectively inhibit the virulence of our target bacteria.

More about our target conditions...

Cholera

Cholera is a bacterial infection of the small intestine caused by the bacterium Vibrio cholerae, which enters the body via ingestion of contaminated food or water. Without proper treatment, severe dehydration and even death can occur within hours due to the infection's three main symptoms of vomiting, nausea and diarrhoea.

Cholera infects around 3-5 million people worldwide and causes around 58,000-130,000 deaths per year.

Shigellosis

Shigellosis is caused by the bacteria belonging to the genus Shigella. It is another food and waterborne illness, which rarely occurs in any animals apart from humans. It is frequently found in water sources that are contaminated with human faeces, and is a major cause of illness in developing countries. The symptoms are very similar to those of cholera, and fatalities are caused in much the same way.

Shigellosis infects around 163 million people worldwide and causes 1 million deaths annually.

Surprisingly, both of these bacterial infections are actually fairly easily fought off by the human immune system. The problem for people in developing countries? They can only be successfully fought off if the affected individual is properly hydrated.

We created two modular synthetic devices called S.O.R.D and spiRNA, that work together to target these infections. You can read all about them here

Part Improvement

In order to see if our cells were secreting osmY (a protein naturally secreted by E. Coli) and so our sRNA, we needed a way to track it. To do this, we added a HA tag to a pre-existing part in the registry from the Washington 2012 team, BBa_K892008, to be able to detect in western blot tests whether our cells were secreting osmY.