E. coli causes disease by a variety of different methods. Which one of the following E. coli types is characterized by the presence of LT (heat-labile) and ST (heat-stable) proteins?

LT and ST proteins are characteristic of enterotoxigenic E. coli. To cause diarrhea, E. coli must produce not only LT and ST toxins but also adhere to the lining of the small intestine. Fimbrial antigens are involved in adherence.