Definition: A genus of gram-negative, rod-shaped, nonfermenting bacteria (family Achromobacteraceae) that are either motile and peritrichous or nonmotile. They are strictly aerobic; some strains are capable of anaerobic respiration in the presence of nitrate or nitrite; their metabolism is respiratory, never fermentative; they do not use carbohydrates. Found mostly in the intestinal canal, decaying materials, dairy products, water, and soil; they can be isolated from human respiratory and gastrointestinal tracts and wounds in hospitalized patients with compromised immune systems; occasionally the cause of opportunistic infections, including nosocomial septicemia. Type species is Alcaligenes faecalis.
[alkali + G. -gen, producing]