Stenotrophomonas maltophilia (Xanthomonas maltophilia, Pseudomonas maltophilia)
An aerobic, gram-negative bacillus oxidase-negative, rarely oxidase-positive, and is ubiquitous in nature. It has been isolated from vegetable and water sources, milk, frozen food and soil. It is frequently isolated from hospital environment including distilled water and nebulizers. It is capable of surviving for a few days on moist inanimate vectors. It can colonize humans without causing infection but can also cause disease.