03型伪结核杆菌毒力基因的研究

A STUDY ON THE VIRULENCE GENE ( S ) FROM 03 SEROTYPE STRAIN OF YERSINIA PSEUDOTUBERCULOSIS

用质粒消除技术,从03型伪结核杆菌毒力株中筛选出同宗的质粒治愈株,后者在缺失了一个分子量约为66kb(43.3MD)的大质粒的同时,丧失了对动物的侵袭性,细菌毒力消失。证实03型伪结核杆菌的毒力基因是位于染色体外的环状质粒DNA上,该质粒还编码了细菌的两个表型,1.外膜蛋白的产生;2.依赖钙离子生长。本文提示:要判定从临床上分离的03型伪结核杆菌是否具有毒力,应以检测其是否具有66kb的毒力质粒为标准。

The plasmid-cured strains selected from 03 serotype virulent strain of Yersinia Pseudotuberculosis did not express tissue invasion after losing the 66 kb plasmid and showed avirulent in an appropriate animal model. The result showed that the virulence gene(s) of 03 serotype strain of Yersinia Pseudotuberculosis was located on the circular plasmid which was self-replicating extra-chromosomal element, in addition, there were two plasmid-encoded traits: ( 1 )expression of plasmid-mediated outer membrane proteins; ( 2 )the Ca++-dependent growth. Our report suggests that the 66kb plasmid is essential for determining whether 03 serotype strain of Yersinia Pseudotuberculosis isolated from clinical case is virulent or not.