猪链球菌2型溶血毒素的产生条件及其特性分析

Effects of cultural conditions on yield of hemolytic toxin by Streptococcus suis and its characterization

猪链球菌 2型江苏分离株HA980 1产生一种溶血毒素 ,培养条件影响其产量。最佳培养条件为Todd Hewitt肉汤(pH 7 5 )中接种 V(种子液 )∶V(肉汤 ) =1∶10 0的种子液 ,37℃静置培养 12h。培养基中的胰蛋白胨对该溶血素的产生起决定性作用。该溶血素可被还原剂活化 ,被氧化剂和胆固醇及蛋白酶K抑制 ,亦被抗链球菌溶血素O阳性血清和抗猪链球菌 2型全菌阳性血清抑制。该溶血素在 - 2 0℃较稳定 ,在 4,2 5和 37℃下均易失活 ,但在还原剂作用下可恢复活性。猪红细胞对其最敏感 ,豚鼠、家兔、人、绵羊、牛、鸡及鲫等红细胞次之 。

Streptococcus suis type 2 strain HA9801 isolated in Jiangsu Province could produce a kind of hemolysin and cultural conditions had great effects on its yield.When Todd Hewitt broth(pH7 5)was inoculated with 1% fresh inocula and stationarily incubated for 12 h at 37 ℃,the highest yield of hemolysin occurred.Furthermore,tryptone in the media had decisive effect on the yield of hemolysin.Hemolysin was activated by reducing agents and inactivated by oxidizing agents,low concentration of cholesterol and proteinase K.Antiserum of streptolysin O and antisera of S.suis type 2 both Holland reference strain and Jiangsu isolate inhibited the hemolytic activity of hemolysin also.Hemolysin was quite stable at -20 ℃,but it was very easy to loose hemolytic activity at 4 ℃,25 ℃ and 37 ℃.However,the lost activity could be nearly restored following the addition of the reducing agents to the 4 ℃,25 ℃ and 37 ℃ storage preparations.Pig erythrocytes were the most susceptible to the hemolysin,followed by red blood cells of guinea pig,rabbits,human,sheep,cattle,chicken and Carrassius auratus, mouse erythrocytes were the least susceptible.