【摘要】 根据已发表的大肠埃希氏菌F18ab菌毛F亚单位 (FedF/ab)的基因 (fedF/ab)序列 ,设计了 1对引物 ,利用PCR技术从大肠埃希氏菌F10 7/ 86、YCED1、YCED2、C、D和 12F株中分别扩增获得了一段序列 ,并克隆至 pGEM T载体 ,获得了重组质粒TF10 7F、TYCED1F、TYCED2F、TCF、TDF、T12FF。经琼脂糖凝胶电泳、序列测定及分析 ,6个重组质粒的大小均为 90 3bp ,与fedF/ab基因大小一致。其中大肠埃希氏菌F10 7/ 86、YCED1、C和 12F株的fedF基因序列完全相同 ;只有YCED2株在第 181位碱基处存在 1个C→T的无义变异差异 ,D株在第 6 5 5位碱基处存在 1个T→C变异差异并在氨基酸水平出现 1个S→P变异。结果表明 ,所克隆的序列均为F18ab菌毛F亚单位的基因更多还原

【Abstract】 A pair of primers was designed and synthesized according to fedF of fimbriae F18ab (fedF/ab). Six nucleoide fragments were amplified from differentEscherichia coli strains, i.e. F107/86, YCED1, YCED2, C, D and 12F. The PCR products were cloned into pGEM-T vector. Color screening, PCR and restriction endonuclease analysis were used to identify the recombinant plasmids. Six recombinant plasmids including TF107F, TYCED1F, TYCED2F, TCF, TDF and T12FF were obtained. The six (recombinant) plasmids sequences were analyzed, and compared with the published sequences of fedF/ab. The data of sequences for the six fedF genes were shown that their size were in accord with the sequences of fedF/ab (903 bp). The fedF of the strains F107/86, YCED1, C, 12F shared 100% identity at nucleoide level respectively, except the strains YCED2 had variance of cytosine to thymine at nucleotide 181, and the strains D had variance of thymine to cytosine at nucleotide 655. All the data in this study conformed the six genes derived from the six differentEscherichia coli strains are all fedF/ab genes of fimbriae F18ab.更多还原