Straight rods that are Gram negative, this bacterium uses glucose but does not frequently produce gas. Produces urease. Growth is best at 35-37 C. Isolation of this microbe has occurred from environmental samples and the intestinal tracts of man and animals. It is an opportunistic pathogen implicated in sepsis and meningitis, urinary tract infections, gastroenteritis, and a variety of other infections. It differs from ssp. morganii in being lysine positive and nonmotile.