沙门氏菌入侵因子基因保守序列的克隆与分析

Cloning and Analyzing of Salmonella Invasive Factor Gene Conservative Sequence from Salmonellosis

分别提取鸡白痢沙门氏菌、鼠伤寒沙门氏菌、猪霍乱沙门氏菌染色体DNA,用设计的专一性引物扩增沙门氏菌入侵因子基因保守序列,PCR产物经凝胶回收纯化,克隆于TE载体,在含X-gal、IPTG的Amp LB平板筛选阳性克隆,提取质粒进行酶切鉴定,对目的片段进行测序。结果表明,扩增出的序列与GenBank中发表的基因序列一致。通过Blast比对,发现从3种沙门氏菌菌株克隆出的片段所编码的氨基酸序列中,鼠伤寒沙门氏菌和猪霍乱沙门氏菌相同,鸡白痢沙门氏菌与前两种相差1个氨基酸。

The chromosomal DNAs of Salmonella pullorosium , Salmonella typhimurium , Salmonella suipesti fer are extracted respectively. According to the specific primers,conservative sequence of salmonella invasive factor gene is amplified from the three chromosomal DNAs by using PCR technique. The purified PCR products was cloned into T vector. Positive clones containing the vector are selected on LB- plus amplcillin （50μg/mL） plates including X- gal ,IPTG. The plasmid DNAs are extracted and digested with enzymes, then analyze the sequences. In conclusion, The amplified DNAs are consistent with GenBank. The conservative amino acids encoded by the conservative sequence of salmonella invasive factor gene are different by BLAST. The conservative amino acids of Salmonella typhimurium and Salmonella suipestifer are identical, but the difference of Salmonella pullorosium with the formers is only an amino acids.