A. faecalis are Gram-negative, small, nonsporing bacilli. Theyare motile due to presence of peritrichous flagella. They are strict aerobes and do not ferment sugars. They are usually oxi-dase positive. A. faecalis occurs as a saprophyte in water and soil contaminated with putrefied decayed organic matter. The bacteria are also found as commensals in the gastrointestinal tracts of humans and animals. The bacterium causes urinary tract infection, infantile gastroenteritis, and typhoid-like fever in humans.