Mouse Models of Escherichia coli O157:H7 Infection and Shiga Toxin Injection

Figure 3

E. coli O157:H7 virulence factor expression and interaction with host cells. E. coli O157:H7 possesses a large plasmid (pO157), carries the LEE PAI (and thus is intimin positive), and expresses Shiga toxins. The LEE locus encodes a TTSS and TTSS effector proteins. One of the TSSS proteins, E. coli Secreted Protein (Esp) A, forms a filament that serves to translocate TTSS effector proteins from the bacterium into the host cell by way of a pore created by EspB and EspD. One of these effectors, Tir, serves as the receptor for the major adhesin, intimin, and thus allows adherence of the bacterium to the host cell.