The Collaborative International Dictionary of English v.0.48:

enterobacteria \enterobacteria\ n. pl.
   rod-shaped gram-negative bacteria of the family
   Enterobacteriaceae; most occur normally or pathogenically
   in intestines of humans and other animals; some, such as
   those of the genus Erwinia, are found in plants.

   Syn: enteric bacteria, enterics.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

enterobacteria
    n 1: rod-shaped Gram-negative bacteria; most occur normally or
         pathogenically in intestines of humans and other animals
         [syn: enteric bacteria, enterobacteria, enterics,
         entric]