狐肺炎大肠杆菌yihe基因缺失株的构建及致病性

Construction and biological characteristics identification of yihe gene knock-out mutant of Escherichia coli strain causing pneumonia in foxes

为研究YihE蛋白在狐肺炎大肠杆菌致病过程中的作用,利用λ-Red同源重组方法构建狐源大肠杆菌yihe基因缺失株,并从生长特性、生化特性、抗吞噬能力、菌株毒力等几方面对突变菌株进行评价。结果表明:与狐肺炎大肠杆菌野生型菌株相比,yihe基因缺失株生长特性和生化特性无明显差异,但其抗吞噬细胞吞噬能力以及胞内存活能力有明显下降,细菌半数致死量有显著提高。本试验成功构建狐肺炎大肠杆菌yihe基因缺失株,为研究YihE蛋白的作用机制奠定基础。

To investigate the roles of YihE protein played in pathogenic processes of E.coli strain causing pneumonia in foxes.λ-Red homologous recombination was used for knockout of yihe gene,followed by comparison of growth characteristics,biochemical characteristics,anti-phagocytosis ability and bacterial virulence.The data showed that,the YihE-deficient mutant displayed no difference in growth characteristics and biochemical characteristics with wild type strains.But compared to the parent strain,sharply impired anti-phagocytosis ability,and significantly increased LD50 was demonstrated in isogenic deletion mutant,indicating the deficient virulence of mutant.In this study,we successfully constructed the yihe gene-deleted mutant of E.coli strain causing pneumonia in foxes,providing foundation for exploring underlying mechanism of YihE protein.