Toxic effect of staphylococcal lysins for goldfish.

Goldfish died within 24 hr after intraperitoneal injections of 0.2 ml of Seitz filtrates of hemolytic Staphylococcus aureus cultures grown on Dolman and Wilson medium under increased CO(2) pressure for 72 to 96 hr. Two lethal toxins differing in heat sensitivity, antigenicity, and degree of toxicity were demonstrated. Studies of the relationship between the lethal factors and the hemolysins in the filtrates suggested that alpha- and beta-lysin were responsible for the lethal effects. Filtrates of nonhemolytic staphylococcal cultures were innocuous. Goldfish were suitable animals for detecting toxicity in staphylococcal culture filtrates and for quantitative studies of the toxins. The results were highly reproducible.