Characterization of Hemolysis and Pathogenicity of Exotoxin Secreted by 36 Strains of Aeromonas

The hemolysis and pathogenicity of exotoxin in bacteria_free culture supernatants from 36 strains of Aeromonas were measured.The results of hemolytic test and animal experiment showed that the exotoxin of 30 strains of them,which were 13 strains of Aeromonas Hydrophila and 17 strains of aeromonas Sobria,had hemolysis.It was found that there was a difference in the hemolysin titers from 12 to 1128 among 30 strains,and a significant correlation between the hemolytic titers and the lethal rates of the exotoxin:the exotoxins with the hemolytic titers of 116 or abover had a lethal rate of 100% for the experimental mice and their titers of 18 or lower had various lethal rates from 0% to 100% In addition,two strains of Aeromonas Sobria could not secrete the exotoxin,but their cultureal supernatant had a lethal rate of 66.6% for mice,this suggests that these bacteria might secrete protease with pathogenicity.