Some effects of polysaccharide preparations from Serratia marcescens and Aerobacter aerogenes on cells in tissue culture.

When certain polysaccharide fractions isolated from cultures of Serra@tia marcescens (6, 2), Aero bader aerogenes, or other Gram-negative bacteria (8) are injected in large doses into mice, symptoms very similar to those of shock occur. The animals are prostrated, their muscular response is much lower than normal, they breathe with difficulty, and the body temperature drops. Similar symp toms are observed when these polysaccharides are injected into sarcomatous mice, but, in addition, zones of hemorrhage and necrosis appear in the tumor itself, sometimes resulting in the destruc tion of the neoplasm. Whether this necrosis oc curs as a result of the direct action of the poly saccharide on the tumor cell or on the action of a complex formed in vivo after the polysaccharide in jection, or results indirectly from a systemic dis turbance, is not yet settled. Tissue culture technics may be helpful in solving it. It appears that the only observations along these lines are those of McConnell (4), who reported no damag ing effect by a polysaccharide from S. marcescens (obtained from Dr. M. J. Shear) on cultures of Sarcoma 87 cells. Our own experiments bring out some facts which may be of interest.