any of a family (Enterobacteriaceae) of Gram-negative, rod-shaped bacteria that includes normally occurring and pathogenic intestinal bacteria, as E. coli and salmonella
See enterobacterium in American Heritage Dictionary 4
nounpl.en·ter·o·bac·te·ri·a(-tîrˈē-ə)
Any of various gram-negative rod-shaped bacteria of the family Enterobacteriaceae that includes some pathogens of plants and animals, such as the colon bacillus and salmonella.