Proteus vulgaris is a Gram-negative bacterium. It inhabits the intestinal tracts of animals and can cause urinary tract infections. As any other Gram-negative bacterium, Proteus vulgaris has a cell envelope composed of a thin peptidoglycan cell wall between the outer membrane and inner cell membrane. It also has an extracytoplasmic outer membrane. Similarly to other prokaryotes, it lacks in a nucleus and other organelles.
