霍乱弧菌毒力表达调控基因及霍乱、黑热病双价口服活疫苗候选株的研究

目的：研究霍乱弧菌毒力表达调控基因与霍乱弧菌毒力之间的关系，构建霍乱、黑热病双价口服活疫革候选株。方法：首先采用PCR扩增、Southern印迹杂交及原位杂交对我国不同群型霍乱弧菌毒力表达调控基因toxR、toxS、toxT的分布进行研究；然后采用自杀性质粒和接合转移技术构建霍乱弧菌toxR基因缺失株，并与原发菌株比较，确定toxR基因对霍乱弧菌毒力表达调控机制；再用基因定向置换技术构建霍乱、黑热病双价口服疫苗候选株。结果：霍乱弧菌毒力表达调控基因与霍乱弧菌毒力表达有关；霍乱弧菌toxR蛋白是霍乱肠毒素的正调控因子，是霍乱弧菌主要外膜蛋白（40kDa、43kDa）编码基因的负调控因子。结论：初步构建霍乱、黑热病双价口服活疫苗候选株。

Study on Virulence Regulatory Genes in Vibrio cholerae and a Bivalent Oral Candidate Vaccine of Leishmania donovani and Virbrio cholerae

Abstract: Objective To analyse the relation of virulence expression regulatory genes and toxin gene expression of Vibrio cholerae , and to construct a bivalent oral candidate vaccine of Leishmania donovani and Vibrio cholerae . Methods 56 strains of Vibrio cholerae were detected with PCR amplification, Southern blot and in situ hybridization; toxR gene deficient strains of Vibrio cholerae IEM101 and 569B were constructed with suicide plasmid pGp704; and finally a bivalent oral candidate vaccine of Leishmania donovani and Vibrio cholerae wsa developed. Results The distribution of the toxin expression regulatory genes toxR toxS and toxT were strongly related to toxin genes expressions of Vibrio cholerae . ToxR is an up regulator for the expression of ctx gene, and a down regulator for the expression of 40 kDa and 43 kDa outermenbrane protein coding gene. Conclusion A bivalent oral candidate vaccine of Leishmania donovani and Vibrio cholerae was constructed.