论文部分内容阅读
作者采用基因工程技术使野型2a型福氏志贺菌染色体基因aroA缺失（△aroA）和侵袭质粒基因virG缺失（△virG）,从而构建了高度减毒的原型活菌苗CVD1203株。该菌株能侵入肠上皮细胞,但不能进行广泛的细胞内复制或侵袭邻近上皮细胞。 用聚合酶链反应（PCR）扩增野型2457T株基因5’端头501及3’端末591个碱基对。多次克隆后以电穿孔技术和反选择筛选出同源性重组克隆CVD1201.1。该克隆呈卡那霉素
The authors used a genetically engineered technology to make the highly attenuated prototypical live vaccine strain CVD1203 strain, which made aaA and a virG of the wild type 2a Shigella flexneri. The strain invades intestinal epithelial cells but does not undergo extensive intracellular replication or invasion of adjacent epithelial cells. Polymerase chain reaction (PCR) was used to amplify the 5’-end 501 and 3’-end 591 base pairs of wild type 2457T strain. After several clones, the homologous recombinant clone CVD1201.1 was screened by electroporation and reverse selection. This clone is kanamycin