The March of the Superbugs

As the post-antibiotic era approaches, humanity 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 misprescription of antibiotics in cases where they have no benefit, such as viral infections. 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, iGEM Sheffield, aim to address this problem by building a device that helps to slow down the 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, we want to create a device that could prevent the unnecessary use of antibiotics.

What are we going to do?

We are engineering bacteria to fight the war against antibiotic resistance. Bacteria are engaged in a constant battle with the human body over the precious resource, iron. Iron-scavenging molecules called siderophores are released by bacteria. The immune system fights back by producing lipocalin-2, which neutralises siderophores. We are engineering a strain of E. coli to be part of a system which detects increased lipocalin-2 levels, characteristic of a bacterial infection, and responds with a change in fluorescence.

Our primary detection system involves the use of Fur, an iron-dependent repressor, linked to the fluorescent reporter protein, GFP, via a RyhB inverter. By measuring the intensity of fluorescence, the type of infection can be determined, i.e. bacterial or non-bacterial, providing evidence to produce a more informed prescription, all within your doctor’s appointment.