enterobacterium

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of various gram-negative, rod-shaped, often enteric bacteria of the family Enterobacteriaceae that includes some plant and animal pathogens, such as salmonella.

from the GNU version of the Collaborative International Dictionary of English.

• noun one of the enterobacteria; a member of the family Enterobacteriaceae.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun microbiology Any of very many gram-negative rod-shaped bacteria of the family Enterobacteriaceae, many of which are pathogenic.