Synergistic effects of Fusobacterium necrophorum lipopolysaccharide, cytoplasmic, and culture supernatant fractions on induction of acute hepatic necrosis in rabbits.

Synergistic effects of toxic fractions of Fusobacterium necrophorum were examined for evaluation of the role of the toxin in inducing liver abscesses in rabbits. Cytoplasmic and culture supernatant fractions of F necrophorum had preparative activity for the Shwartzman reaction, and lipopolysaccharide of F necrophorum had preparative and provocative activities for the reaction. All 3 fractions were hepatotoxic. Inoculation into the bile duct with each fraction followed by intravenous inoculation with F necrophorum or Escherichia coli lipopolysaccharide had a greater synergistic effect in inducing severe hepatic necrosis than did inoculations with double doses of the cytoplasmic or supernatant fractions of F necrophorum. This synergism may have been attributable to the Shwartzman reaction.