A genus of Gram-negative, rod-shaped, non-fermenting bacteria (family Achromobacteraceae) which 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 utilize carbohydrates. They are 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. The type species is Alcaligenes faecalis.


[alkali + G. -gen, producing]