Walsh & Hoyt: Fusobacterium

Fusobacterium species are nonspore-forming, nonmotile, gram-negative, anaerobic bacilli that are normal colonizers of the upper respiratory tract. They tend to be pleomorphic in culture, appearing as short, long, or even filamentous rods. The pathogenicity of these organisms is related, in part, to their cell wall, which contains conventional gram-negative lipopolysaccharide with potent endotoxic properties, and, in part, to their ability to produce a coagulase enzyme that agglutinates erythrocytes and induces clotting. Infection by fusobacteria thus is associated with a high incidence of thrombosis of both arteries and veins. The internal jugular vein is especially likely to become occluded by the infection. This condition, called ""Lemierre syndrome,"" is usually associated with severe sepsis that, if not treated aggressively, often ends in death.