Any of a large and varied group of rod-shaped, often curved bacteria .
Many can move, propelled by one or more flagella. Some aquatic species are attached to surfaces by long strands or stalks. Most are found in soil or water; some cause diseases in plants, and a few cause serious diseases in humans and other mammals. One very common and widespread species, Pseudomonas aeruginosa , is a serious cause of disease in humans, causing antibiotic-resistant infections in individuals with weakened resistance. Pseudomonads have been implicated in hospital-acquired infections of surgical wounds and severely burned tissue and in fatal infections of cancer patients treated with immunosuppressive drugs.