表达大肠杆菌LT-B抗原的减毒鼠伤寒沙门氏菌株的构建

Construction of Avirulent Salmonella typhimurium Strain Expression Escherichia coli LT-B Antigen

采用无毒的鼠伤寒沙门氏菌SR-11 △Cya,ACrp,Aasd菌株作为宿主菌,选择相应的asd^+表达载体构建了含大肠杆菌肠毒素B亚基基因(toxB)的重组质粒,并通过两次转化引入宿主菌,构成了平衡致死的重组体。特异性的测定表明,这种无抗药性的杂合菌株能较高水平地表达LT-B抗原,可望成为预防ETEC腹泻和相应的沙门氏菌病双价口服活疫苗的研究基础。

A avirulent Δcya Δcrp Δasd strain of Salmonella typhimurium SR-11 was used as host. The recombinant plasid containing heat-labile entero toxin B subunit gene and asd^+ gene was constructed, and was introduced into the host by twice transformation. The hybrid strain is a balanced lethal recombinant. Detections by special methods showed that the hybrid strain having no drug resistance gene could express LT-B antigen at high level. The hybrid strain is worth considering as a foundation for studying on bivalent live oral vaccine strain against ETEC diarrhoea and erlative Salmonella disease.