Alcaligenes

Alcaligenes is a genus of Gram-negative, aerobic, rod-shaped bacteria. The species are motile with one or more peritrichous flagella and rarely nonmotile. It is a genus of nonfermenting bacteria (in the family Alcaligenaceae). Additionally, some strains of Alcaligenes are capable of anaerobic respiration, but they must be in the presence of nitrate or nitrite; otherwise, their metabolism is respiratory and never fermentative; The genus does not use carbohydrates. Strains of Alcaligenes (such as A. faecalis) are found mostly in the intestinal tracts of vertebrates, 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. They are occasionally the cause of opportunistic infections, including nosocomial septicemia.