宋内氏福氏2a双价志贺氏菌芳香族氨基酸营养缺陷型减毒株的构建

CONSTRUCTION OF AN AROMATIC ACID AUXOTROPHIC ATTENUATED STRAIN OF THE BIVALENT HYBRID STRAIN(FS54)OF S. SONNEI AND S. FLEXNERI 2A

ＦＳ５４是本室构建的宋内氏福氏２ａ双价志贺氏菌杂交株，具有志贺氏菌的毒力。本研究通过遗传重组，给ＦＳ５４株引入了ａｒｏＤ基因的转座于Ｔｎ１０插入失活物（ａｒｏＤ：：Ｔｎ１０），构建了ＦＳ５４株的芳香族氨基酸营养缺陷型减毒株，并进一步去除了Ｔｎ１０所携带的四环素抗性和宋内氏１相大质粒（ｐＳＳ１２０：：Ｔｎ５）上所携带的卡那霉素抗性，得到了宋内氏福氏２ａ双价志贺氏菌芳香族氨基酸营养缺陷型减毒株Ｆｓ５４－７ｂ．

he virulent strain of FS54 constructed in our laboratory is a bivalent hybrid strain of S.sonnei and S.flexneri 2a. In this paper,we made a series of aromatic acid auxotrophic attenuated strains by introducing Tn 10 inactivatedaroD gene into FS54 strain. Furthermore ,we successfully eliminated the tetracycline resistant gene (carried byTn 10)and kanamycin resistant gene(carried by Tn5 on form I plasmid pSS120::Tn5),and eventually obtained aTc sensitive,Km sensitive aromatic-dependent attenuated bivalent strain of S. sonnei and S. flexneri 2a,i.e. FS54-7b strain.