A genus of aerobic, facultatively anaerobic, non-spore-forming, motile bacteria (family Enterobacteriaceae) containing gram-negative rods. The cells are peritrichous, and some strains have encapsulated cells. Glucose is fermented with the production of acid and gas. The Voges-Proskauer test result is usually positive. Gelatin is slowly liquefied by the most commonly occurring forms (Enterobacter cloacae). These organisms occur in the feces of humans and other animals and in sewage, soil, water, and dairy products; recognized as an agent of common nosocomial infections of the urinary tract, lungs, or blood; somewhat resistant to antibiotics. This genus characteristically acquires resistance rapidly in part because of the presence of inducible ß-lactamases; the type species is Enterobacter cloacae.