This short, straight rod occurs singly, in pairs, and in short chains. It is nonmotile. Gram reaction is negative. Gas is produced from sugars; hydrogen sulfide is not produced. It is an opportunistic pathogen found in feces of man and animals without any symptoms of disease, and in water, sewage, soil, and food. This organism can cause a variety of diseases, including but not limited to pneumonia. A typical sufferer has predisposing factors reducing their resistance, such as alcoholism, diabetes, malignancy, chronic infection or disease, or immune suppression therapy. Growth is at 35-37 C.