General Information: This organism can become an opportunistic pathogen, infecting anywhere in the body and causing abcess formation. Enterotoxigenic Bacterioides fragilis (ETBF) is associated with diarrheal diseases. This strain was isolated from a patient with septicemia in Japan. Common gut bacterium. This group of microbes constitute the most abundant members of the intestinal microflora of mammals. Typically they are symbionts, but they can become opportunistic pathogens in the peritoneal (intra-abdominal) cavity. Breakdown of complex plant polysaccharides such as cellulose and hemicellulose and host-derived polysaccharides such as mucopolysaccharides is aided by the many enzymes these organisms produce. Although only a minor component of the human gut microflora, this organism is a major component of clinical specimens and is the most common anaerobe isolated.