Exotoxic activities ofCorynebacterium pseudotuberculosis

Abstract

Several methods were used to investigate the relationships between staphylococcal beta-hemolysin inhibitory (BHI) activity, phospholipase D, dermonecrosis, and lethality, which have all been used as indicators of exotoxin in culture filtrate ofCorynebacterium pseudotuberculosis. Culture filtrate was subjected to treatment with formalin, heat, and fractionation by (NH4)2SO4 precipitation, ultrafiltration, and Sephadex G-100 chromatography. Formalin treatment of culture filtrate resulted in loss of phospholipase D and dermonecrotic activities, but no decrease in BHI activity. Culture filtrate and formalin-treated culture filtrate blocked complement-mediated immune hemolysis. Heat treatment of culture filtrate destroyed phospholipase-D activity and reduced BHI activity. Phospholipase-D and dermonecrotic activities eluted from Sephadex G-100 as two distinct adjacent peaks preceding the main protein peak. Maximum lethal activity did not correspond to phospholipase D, but was closely associated with dermonecrotic and maximum BHI activity. Dermonecrotic and BHI, but not phospholipase-D activities were detected in a 1000-dalton filtrate of culture filtrate.