Escherichia

noun

Esch·​e·​rich·​ia ˌesh-ə-ˈrik-ē-ə 

: a genus of aerobic gram-negative rod-shaped bacteria of the family Enterobacteriaceae that form acid and gas on many carbohydrates (as dextrose and lactose) but no acetoin and that include occasionally pathogenic forms (as some strains of E. coli) normally present in the human intestine and other forms which typically occur in soil and water