Comparison of the exotoxins of four strains of Corynebacterium pseudotuberculosis

The activity of exotoxins produced by four strains of Corynebacterium pseudotuberculosis were compared by their ability to kill white mice, their haemolytic activity, staphylococcal haemolysin-inhibiting effect and activity in an enzyme-linked immunosorbent assay (ELISA). Exotoxins with a haemolytic titre of 1 in 256 or more killed all mice and had the most inhibitory effect (1 in 64 or more) on staphylococcal haemolysin. The haemolytic test and staphylococcal haemolysin inhibitory test of exotoxin activities were highly correlated (P less than 0.001) with the mouse toxicity of the four exotoxins examined. No significant correlation was evident between the ELISA and relative toxicity of the exotoxins.