(Janice Haney Carr/CDC via AP) This colorized 2006 scanning electron microscope image made available by the Centers for Disease Control and Prevention shows E. coli bacteria of the O157:H7 strain that produces a powerful toxin which can cause illness. The city of Lehi is urging residents not to drink or recreate in pressurized irrigation water amid an E. coli outbreak that has sickened at least 12 people.