Team:Sheffield/Description

	Introduction

Brainstorming & Selection Process

When brainstorming for project ideas, we approached the project from different directions to generate as many ideas as possible. For instance, we looked at current and imminent world issues, from infectious diseases to plastics recycling. We researched recent scientific developments to find synthetic biology solutions that can then be applied to problems, as well as looking at past iGEM projects to see if we could build upon those ideas. We then narrowed down the list of ideas based on whether it was feasible within the project timeframe and whether the idea was able to involve and engage all team members and their areas of expertise. Based on this shortlist, we researched and expanded on each idea in detail before voting for our favourite idea.

We decided to focus on the issue of antibiotic resistance and the lack of diagnostic tools to differentiate between bacterial and viral infections. When the cause of an infection is unknown, antibiotics are usually prescribed as a preventative measure. However, this contributes to the rise of antibiotic resistant bacteria.

What We Hope to Accomplish

iGEM Sheffield 2016 aims to combat the issue of a lack of diagnostic tools by building a bedside device that can discriminate between a bacterial infection and a viral infection within 15 minutes of extracting the patient’s blood sample. We plan to design Escherichia coli receptors to detect siderophores, which are molecules produced by bacteria to scavenge iron from low-iron environments such as the bloodstream. E. coli has many siderophores however we will only be focusing on the siderophore enterobactin for simplification.

Our biosensor involves the use of engineered E. coli strains that produce a detectable color change in response to the uptake of enterobactin-iron complexes. To improve the sensitivity of this system, the number of enterobactin-iron complexes being internalized by E. coli will be maximized before the actual detection step. This can be done by decoupling lipocalin-enterobactin complexes and saturating enterobactin with iron. Our detection system involves the use of the protein hemerythrin, a high-affinity iron-binding protein, that produces a colour change when bound to iron. By comparing the color against a standard, the cause of infection can be determined.

As the hemerythrin system turned out to be challenging, we established an alternative sensing system utilising antisense RNA (RhyB).