Escherichia coli (E. coli) /eshirī″kē·ə kō″lī/ [Theodor Escherich, German physician, 1857–1911; Gk, kolon, colon] , a species of coliform bacteria of the family Enterobacteriaceae, normally present in the intestines and common in water, milk, and soil. E. coli is the most frequent cause of urinary tract infection and is a serious gram-negative pathogen in wounds. E. coli septicemia may rapidly result in shock and death through the action of an endotoxin released from the bacteria. See also enterohemorrhagic Escherichia coli.