携带大肠杆菌融合基因K88ac-STII的减毒鼠伤寒沙门疫苗菌的构建与鉴定

Construction and Identification of a Reconbinant Live Attenuated Salmonella typhimurium Vaccina Strain Carrying K88ac-STII Fusion Gene of Enterotoxigenic Escherichia

为构建表达大肠杆菌菌毛蛋白K88ac和热稳定肠毒素STII的无抗性减毒鼠伤寒沙门氏菌疫苗株,采用缺失腺苷酸环化酶基因(Δcya)、环腺苷酸受体蛋白基因(Δcrp)以及天冬氨酸β-半醛脱氢酶基因(Δasd)的鼠伤寒沙门菌(X4550)作为宿主,将编码K88ac-STII的融合基因插入Asd+组成型表达载体pYA3334中,通过2次转化引入宿主菌,成功构建了表达K88ac-STII融合基因平衡致死的减毒鼠伤寒沙门重组菌株S.typhimuriumX4550(pYA3334K88ac-STII),为防治仔猪腹泻提供了口服活菌疫苗候选株。

To construct a non-resistance and attenuated Salmonella typhimurium strain which Carrying K88ac-STII Fusion Gene of enterotoxigenic Escherichia coli(ETEC).The K88ac-STII Fusion gene was amplified by PCR and inserted into the expression vector pYA3334 containing asd gene and was introduced into the delta Cya,delta Crp,delta Asd attenuated Salmonella typhimurium strain X4550 by electroporation through transformations twice,which is a balanced lethal recombinant.Results showed S.typhimurium X4550(pYA3334-K88ac...