鼠疫菌9．5kb质粒对假结核菌粘附、侵袭上皮细胞能力的影响

Efects of a Cloned pPCPI on the Ability of Y。 pseudotuberculosis Adhesion and Invasion to Epithelial Cells

用电穿孔方法把克隆的鼠疫菌９．５ｋｂ质粒转移到不同血清型的假结核菌中，研究了不同实验条件下９．５ｋｂ质粒对假结核菌粘附、侵袭上皮细胞（Ｈｅｐ—２）能力的影响。结果显示，尽管９．５ｋｂ质粒不能明显改变假结核菌的粘附、侵袭特征，但相对于亲本株而言，转化后的菌株在所有实验条件下侵袭上皮细胞的能力确实有所下降，表明９．５ｋｂ质粒介导的粘附、侵袭机制有别于假结核菌。由此，分析和评价了９．５ｋｂ质粒在粘附、侵袭过程中的作用，并就粘附、侵袭能力与细菌毒力的关系进行了讨论。

t has been shown that pPCPl(Y.pestis 9.5kb plasmid)is a invasive factor,responsible for bacteria diss-minating from the primary superficial site of infection.In this study,we have transformed the eloned pPClinto Y. pseudotuberculosis by electroporation,and examination of the ability of adhesion and invasion on Hep-2cell model system.No significant difference was found between transformant and their parent strains eitherin the viable count assay or microscopic observation.A slight reduced invasive ability consistently came to thetransformants in various conditions,although bacteria-grown conditions,serotype,and the time of bacteriacell ineraction had an obvious influence on cellular penetration. Suggesting that distinct mechanisms are usedby Y. pestis and Y. pseudotuberculosis for cellular invasion.Furthermore,we also discussed the relationship be-tween cellular adhesion,penetration and bacterial pathogenecity.