迟钝爱德华氏菌菌蜕系统的构建

Establishment of Edwardsiella tarda Ghosts System

菌蜕系统(Bacterial Ghost,BG)的形成是利用噬菌体PhiX174的裂解蛋白E在革兰阴性菌细胞膜形成一个跨膜孔道结构,使细菌胞内物质由孔道排出而引起死亡。这种基因灭活的过程不引起细菌表面结构的任何理化变性,因此生成的细菌空壳具有与活菌相同功能的膜抗原结构,可诱导机体的体液免疫和细胞免疫应答。检测和比较了在铁调控启动子PyncE和温度调控启动子PR/cI控制下的E基因对迟钝爱德华氏菌菌蜕系统(EBG)的生成效率。结果显示,2种启动子均能成功生成EBG,电镜下可观察到细菌两端有直径约为80～400 nm的孔洞。传统菌蜕系统所用的热启动子在诱导后3 h开始裂解,8 h后细菌停止死亡;而新型铁诱导启动子在诱导后2 h细菌即完全停止生长。本研究为将来开发菌蜕载体疫苗防治爱德华氏菌症奠定了基础。

The formation of bacterial ghosts system（BGS） was a trans-membrane passage structure formed on Gram-negative bacterial cell membrane using lytic protein E of macrophage PhiX174 to make the bacterial intracellular substance drained from the passage and caused the cell to die.The process of gene inactivation caused not any physical and chemical denaturation on bacterial surface,therefore,the produced bacterial envelope possessing the same function of living bacterial membrane antigen structure and induces body fluid immune and cell immune of organism to response.The objective of this study was to examine and compare the production efficiency of E gene to Edwardsiella tarda ghosts（EBG） under the control of iron-regulated promoter PyncE and temperature-regulated promoter PR/cI.The results showed that the two promoters could successfully generated EBG,and it was observed through electron microscope that there were two holes with 80～400 nm in diameter on both ends of the bacterium.Heat promoter used in traditional BGS started to split 3 h after the induction,and stop to die 8 h after.And the bacteria totally stopped to grow 2 h after the induction with new iron induced promoter.This study had laid a foundation for the future development of bacterial ghost vaccination to control edwardsiellosis.