MODE OF ACTION OF AN INHIBITOR FROM AGAR ON GROWTH AND HEMAGGLUTINATION OF GROUP A ARBOVIRUSES

A polysaccharide obtained from agar inhibits growth or plaque formation by the equine encephalitis viruses in liquid or solid medium. When free EEE virus is mixed with the inhibitor and incubated at 37C, its capacity to form plaques and to agglutinate goose red blood cells is reduced. The evidence presented suggests that the mode of action of inhibition by the polysaccharide is through direct combination with the free virus particles. Evidence is also presented that shows an inhibition of virus growth that occurs as a result of interaction between the polysaccharide and chick fibroblast cells.