一种缓症链球菌毒素蛋白的分离纯化及其致病性的初步研究

Isolation and purification of a toxin from Streptococcus mitis and preliminary study on its pathogenicity

目的分离与纯化致中毒性休克综合征缓症链球菌外毒素蛋白，并对其致病性进行初步研究。方法将分离的缓症链球菌在ＢａｃｔＡＰＩ２０培养基增菌培养后，所得上清液分别用２０％、４０％、６０％、８０％硫酸铵分段盐析，进一步快速蛋白液相色谱系统（ＦＰＬＣ）最终纯化，分别皮下注射新西兰兔观察有否体温升高、耳部及粘膜充血、腹泻等致热性表现。结果增菌培养上清液２０％盐析段蛋白（外毒素）有致热性作用，可复制新西兰兔致热模型。结论缓症链球菌外毒素蛋白是一种新的链球菌致热性外毒素。

Objective In order to isolate and purify an exotoxin of Streptococcus mitis which can cause toxic shock syndrome and investigate its pathogenicity. Methods The Streptococcus mitis isolated from patient's throat was shaking cultivated in Bact API 20 culture medium, the supernant fluid of which was precipitated with 20%、40%、60%、80%(NH 4) 2SO 4, respectively. The fast protein liquid chromatography(FPLC) was used for final purification. The finally purified proteins were used to challenge rabbits suboutaneously and the responses of fever, diarrhea and reddening of the ears as well as mucous membranes were monitored.Results 20%(NH 4) 2SO 4 precipitated protein(exotoxin) of culture supernant fluid had a pyrogenic effect on rabbits.Conclusion Streptococcus mitis exotoxin is a novel Streptococcus pyrogenic exotoxin(SPE).