"Only One Deadly Strain of E. Coli Is Illegal"
"The food-safety world knows there are a half-dozen or more lethal forms of E. coli ending up in our meat or on our leafy greens that are so virulent they can send people to the hospital and even kill them. But in the United States only one, E. coli O157:H7, is officially termed an adulterant, meaning any raw ground beef that tests positive for it cannot be sold for human consumption."