E Coli is not a deadly food poisoning bacteria; it's an essential part of your gut. There are toxin-producing e coli, and also salmonella, but I don't think those get used in iGEMS competitions.
[0] https://www.hopkinsmedicine.org/health/conditions-and-diseas...
The best known strain in this category is O-157:H7.
Of course, I may have made some errors, my background is in biochem not microbio.
https://en.wikipedia.org/wiki/Shigatoxigenic_and_verotoxigen...