重组双基因鸭源大肠杆菌菌蜕的制备

目的 利用裂解E基因和葡萄球菌核酸酶A(SN)基因的表达,制备鸭源大肠杆菌(E.coli)菌蜕。方法 通过将带有裂解 E基因和葡萄球菌核酸酶A(SN)基因的质粒 pET29a-E-S 转化至鸭源E.coli O₉₂中,对E.coli O₉₂(pET29a-E-S)进行诱导,每隔 30 min 检测菌液的OD₆₀₀值,并检测培养液中所含 DNA。结果 通过诱导,E.coli O₉₂(pET29a-E-S) OD₆₀₀值在诱导 90 min 后开始持续下降,180 min 时开始趋于平稳,到 360 min 溶菌效率达 99.999%。并且葡萄球菌核酸酶把 DNA 降解为 50 ~400 bp 的小片断。结论 通过裂解 E基因和 SN 基因表达,成功制备了E.coli O₉₂菌蜕,本实验为进一步研究该菌蜕疫苗奠定了基础。

Generation of bacterial ghost from Escherichia coli in ducklings by expression of Lysis gene E and Staphylococcal nuclease A gene

We generated bacterial ghost from Escherichia coli in ducklings by expression of Lysis gene E and Staphylococcal nuclease A gene. Plasmid pET29a-E-S consisting of E gene and Staphylococcal nuclease A gene was transferred into E.coli O₉₂ from ducklings. E.coli O₉₂(pET29a-E-S) was induced to lyse and the OD₆₀₀ value of culture media was measured every 30 min during the induction, and DNA in medium were detected. The result showed the OD₆₀₀ value of E.coli O₉₂(pET29a-E-S) began to decline after 90 min of induction, after 180 min of induction, the OD₆₀₀ value decline speed became slowly, and after 360 min of induction, the rate of genetic inactivation was at 99.999%. DNA in medium was degraded into small fragments (50 bp-400 bp) by Staphylococcus nuclease A. The E.coli O₉₂ ghost was generated successfully by expression of Lysis E gene and Staphylococcal nuclease A gene, which laid a foundation on the study of bacterial ghost vaccine against E.coli O₉₂ infection.