The March of the Superbugs

As the onset of the post-antibiotic era approaches, we may be forced to take a step back in modern medicine and enter a world where antibiotics are no longer useful. The World Health Organisation has declared antibiotic resistance as “one of the biggest threats to global health”. A major factor contributing to this is the mis-prescription of antibiotics when they are least needed - in the case of a viral infection. With overlapping symptoms to many bacterial infections, the common cold or flu can often be misinterpreted in the short span of doctor’s appointment.

We at iGEM Sheffield aim to address this problem by building a device that helps to slow down the future development of antibiotic resistance. We are directly addressing the absence of a useful diagnostic tool in the market by building a device that can detect a bacterial infection from a sample of bodily fluid, within a short time-span. Thus, preventing unnecessary use of antibiotics.

What are we going to do?

How we plan to do this is by engineering bacteria to fight our war against them! Bacteria are engaged in a constant battle with the human body over the precious resource, iron. Iron-scavenging machines called siderophores are released by bacteria. The immune system fights back by producing lipocalin, which neutralises siderophores. We are engineering a strain of E coli to be part of a system which detects increased lipocalin levels, characteristic of a bacterial infection, and responds with a change in fluorescence.

Our detection system involves the use of Fur, an iron-dependent repressor, linked to the fluorescent reporter protein, GFP, via a RyhB invertor. By measuring the intensity of fluorescence, the cause of infection can be determined, i.e. viral or bacterial, confirming the need of an antibiotic, producing a more informed prescription all within your doctor’s appointment.