Biological activity of the slime and endotoxin of the periodontopathic organism Eikenella corrodens

Abstract

A partially purified water-soluble slime extract was obtained from two strains of the oral pathogen Eikenella corrodens, designated CS10 A and CS10 B. Endotoxin was also isolated from this organism by the phenol-water extraction procedure. Assays including the local Shwartzman skin reactivity, chicken embryo lethality, Limulus lysate clotting, spleen cell mitogenicity, and immune adjuvancy were used to test the biological properties of these two bacterial extracts. In each of these assay systems the endotoxins of the Eikenella corrodens strains demonstrated the classical endotoxic responses. In contrast, the effect of slime extract in the corresponding assays was either extremely low or absent with the exception of a very strong immunosuppressive effect. Mice treated with slime extract showed a severely reduced immune response to sheep erythrocytes as measured by the hemolytic plaque-forming cell assay.