Shigella vs. EHEC in Colonic Mucosal Invasion

In FA, it's stated that one of the major ways EHEC differs from Shigella is how it "does not invade host cells." I've also seen in explanation to one of the UWorld questions how Shigella differs from many other enteropathogenic organisms becuase it causes disease through "direct invasion of colonic mucosal cells."

But how does EHEC, without also "invading" mucosal cells, inhibit the protein synthesis taken place in the mucosal cells by removing adenine from rRNA of 60S ribosomal...

Shigella vs. EHEC in Colonic Mucosal Invasion

Shigella vs. EHEC in Colonic Mucosal Invasion