Studies on the pathogenesis of streptococcal infection in cultured yellowtails, Seriola spp.: effect of crude exotoxin fractions from cell‐free culture on experimental streptococcal infection

Abstract

Abstract. Exotoxins prepared from streptococcal bacteria of Seriola spp. origin were grown in fluid culture and fractionates of the supernatant used in toxicity studies in Seriola by oral and percutaneous exposure. Toxic fractions were then applied simultaneously with oral challenge with Streptococcus spp. bacteria. Two fractions E and G were shown to have a significant effect on the pathogenesis of infection.