Bacteriology

Bassler laboratory | Princeton University | Jul – Sep 2013

The bacteria that reside in and on your body are more than mere free-loaders. The relationship between you and your microflora is an extremely dynamic one. Indeed, recent scientific advances have revealed that your gut bacteria may dictate your weight and mental state. The negative consequences of certain bacteria are perhaps even more famous: cholera, TB and chlamydia are among over 200 distinct classical bacteria induced diseases.

How do such small organisms have such measurable effects on the human body? It turns out they work together. Scientists recently discovered that bacteria exist in 2 genetic states; one in which they carry out individual behaviours and the other in which they carry out group behaviours. Bacteria are able to transition between the two behavioural states by ‘reading’ the concentration of simple chemicals, called ‘autoinducers’, in their environment. Every bacterium continuously pumps these chemicals out into their surroundings – so the higher the ‘autoinducer’ concentration, the more bacteria there are present. Different concentrations of the chemicals correspond to different bacterial behaviours, such as making, or not making, a disease-causing agent.

I worked on two projects during my time in the Bassler lab. In the first, I worked on understanding the mechanisms through which bacteria ‘read’ autoinducer concentration and respond accordingly. I also helped screen drugs to see if it is possible to interfere with the inter-bacterial communication and thus regulate disease-causing behaviours. A Winston Churchill Travelling Fellowship supported my time here.