An aerobic gram-negative bacillus that grows readily on most microbiological media. It produces white or bright to light yellow pigmented colonies that have either a smooth, mucoid, rubbery, rough or dry consistency. Isolates from environmental sources grow best at 20oC to 30oC while isolates from clinical sources grow best at 35oC. They are part of the normal intestinal flora of humans and animals. They have been isolated from soil, water, sewage vegetables, meats, plants, flowers, seeds, dairy products, and cosmetics. They are important causes of nosocomial (hospital-acquired) infections especially in immunologically compromised humans.