Chemical properties of the principle in C. parvum that produces splenomegaly in mice.

Suspensions of Wellcome C. parvum strain 6134 produce splenomegaly in mice when injected i.p. in amounts as low as 20 microgram. This lymphoreticular stimulatory activity is extremely sensitive to cell breakage and is abolished by heating for 4 h at 100 degrees. Periodate oxidation of the bacteria destroys their capacity to produce splenomegaly and abrogates the agglutination of intact C. parvum by Con A. Mild HCl hydrolysis also abolished the splenomegaly but phenol:chloroform:ether and chloroform:methanol extractions did not. These results suggest that the relevant stimulatory principle in C. parvum is of carbohydrate nature, and most probably present on the surface of the bacterium.