 Escharichicoli is a bacterium that can cause various diseases when it enters the body. It has been found that certain strains of this bacterium have more virulent traits than others. These traits are often encoded by genes located on plasmids or chromosomes. In particular, one group of strains, known as STC58, has been shown to be particularly dangerous. This group of strains contains a gene called the Hypathogenicity Island, HPI, which encodes proteins that allow the bacterium to bind to iron and other metals. Additionally, the strains also contain two other genes, air and sit, which encode proteins that help the bacterium to survive in the environment. When all three of these genes are present together, they create a highly virulent strain of E, Coli. This article was authored by Gilhem Royer, Olivier Clermont, Julie Morin, and others.