Fusobacterium
Fusobacterium is a genus of anaerobic, Gram-negative, non-sporeforming bacteria, similar to "Bacteroides". Individual cells are slender, rod-shaped bacilli with pointed ends. Strains of "Fusobacterium" cause several human diseases, including periodontal diseases, Lemierre's syndrome, and topical skin ulcers. Although older sources state that "Fusobacterium" is part of the normal flora of the human oropharynx, the current consensus is that "Fusobacterium" should always be treated as a pathogen. "F. prausnitzii", a gut commensal associated with healthy patients, was completely reclassified as "Faecalibacterium" ("Clostridiales":"Ruminococcaceae") in 2002. Clinical relevance. In 2011, researchers discovered that "Fusobacterium" flourishes in colon cancer  cells, and is often also associated with ulcerative colitis, although researchers have not determined if the organism actually causes these diseases or if it simply flourishes in the environment these diseases create. The bacterium is a big anchor for biofilms. It is susceptible to clindamycin. In contrast to "Bacteroides" spp., "Fusobacterium" has a potent lipopolysaccharide.