Klee S R, Tzschaschel B D, Singh M, Fält I, Lindberg A A, Timmis K N, Guzmán C A
Division of Microbiology, GBF-National Research Centre for Biotechnology, Braunschweig, Germany.
Microb Pathog. 1997 Jun;22(6):363-76. doi: 10.1006/mpat.1996.0127.
Bivalent vaccine candidates were developed against Shigella dysenteriae 1 and Shigella flexneri, which are among the most frequent causative agents of shigellosis in developing countries. The rfp and rfb gene clusters, which code for S. dysenteriae serotype 1 O-antigen biosynthesis, were inserted into an arsenite resistance minitransposon and randomly integrated into the attenuated S. flexneri aroD serotype Y strain SFL124. Nine recombinant clones that efficiently expressed both homologous and heterologous O-antigens were obtained. Southern blot analysis showed that in one clone the S. dysenteriae 1 genes had integrated into the chromosome, whereas in all the others they had integrated into the virulence plasmid. All recombinant clones exhibited normal growth characteristics, were able to invade and survive within eukaryotic cells to the same extent as the parental strain, and expressed efficiently the recombinant lipopolysaccharide within invaded cells. Immunization of mice with two of the recombinant clones resulted in the production of antibodies specific for both homologous and heterologous O-antigens. The recombinant clones constitute promising vaccine candidates which can readily be distinguished from endemic shigellae by their non-antibiotic resistance marker.
开发了针对痢疾志贺氏菌1型和福氏志贺氏菌的二价疫苗候选物，这两种菌是发展中国家志贺氏菌病最常见的病原体。编码痢疾志贺氏菌1型O抗原生物合成的rfp和rfb基因簇被插入到一个抗亚砷酸盐微型转座子中，并随机整合到减毒的福氏志贺氏菌aroD血清型Y菌株SFL124中。获得了九个能有效表达同源和异源O抗原的重组克隆。Southern印迹分析表明，在一个克隆中，痢疾志贺氏菌1型基因整合到了染色体中，而在所有其他克隆中，它们整合到了毒力质粒中。所有重组克隆均表现出正常的生长特性，能够在真核细胞内侵入并存活，其程度与亲本菌株相同，并能在侵入的细胞内高效表达重组脂多糖。用其中两个重组克隆免疫小鼠可产生针对同源和异源O抗原的特异性抗体。这些重组克隆构成了有前景的疫苗候选物，通过其非抗生素抗性标记可以很容易地与地方性志贺氏菌区分开来。
