Query: NC_006347:143876 Bacteroides fragilis YCH46, complete genome
Lineage: Bacteroides fragilis; Bacteroides; Bacteroidaceae; Bacteroidales; Bacteroidetes; Bacteria
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.
Subject: NC_015571:1030527 Porphyromonas gingivalis TDC60, complete genome
Lineage: Porphyromonas gingivalis; Porphyromonas; Porphyromonadaceae; Bacteroidales; Bacteroidetes; Bacteria
General Information: This organism is associated with severe and chronic periodontal (tissues surrounding and supporting the tooth) diseases. Progression of the disease is caused by colonization by this organism in an anaerobic environment in host tissues and severe progression results in loss of the tissues supporting the tooth and eventually loss of the tooth itself. The black pigmentation characteristic of this bacterium comes from iron acquisition that does not use the typical siderophore system of other bacteria but accumulates hemin. Peptides appear to be the predominant carbon and energy source of this organism, perhaps in keeping with its ability to destroy host tissue. Oxygen tolerance systems play a part in establishment of the organism in the oral cavity, including a superoxide dismutase. Pathogenic factors include extracellular adhesins that mediate interactions with other bacteria as well as the extracellular matrix, and a host of degradative enzymes that are responsible for tissue degradation and spread of the organism including the gingipains, which are trypsin-like cysteine proteases.