PURIFICATION AND BIOLOGICAL CHARACTERISTIC OF A HEMOLYTIC TOXIN OF STRIPTOCOCCUS SUIS TYPE 2 OF JIANGSU STRAIN

Streptococcus suis type 2 was a pathogen of zoonose,but its virulence factor had been poorly understood.An extracelluar hemolysin was purified from the supernatant of 12h-culture of strain HA9801 of Streptococcus suis type 2 which was isolated from diseased pigs with septicemia in Jiangsu province in summer 1998,by using ammoniumsulfate precipitation,anion-exchange chromatography on DEAE-celluloseand Sephadex G-100 gel filtration chromatography.The purified hemolysin possessed cytotoxic activities on Vero cells and caused death in guinea-pigs in 30 hours after intraperineal injection.The guinea-pigs immunized with the inactivated purified hemolysin became almost to be protected against a lethal challenge of the bacteria.It suggestes that the hemolysin from the Jiangsu Isolate of Streptococcus suis type 2 can be an important virulence/protective factor.