Analysis of the mechanism that elaborate an alternative pathogenicity by loss of capsule in Streptococcus suis

点击翻译按钮获取中文摘要

Streptococcus suis is a bacterial pathogen that causes meningitis or endocarditis in pigs and humans. Capsule, a surface component produced by this bacterium, is an important virulence factor that inhibits phagocytosis of white blood cells. This study showed that acapsular cells of S. suis, which have sometimes been found in swine endocarditis isolates, have spontaneous mutations in capsular polysaccharide synthesis (cps) genes, and that mutations in some cps genes appeared lethal for the bacteria, whereas these lethal effects were relieved by mutations in the other cps genes. Moreover, acapsular cells showed elevated adherence to porcine and human platelets, a major virulence determinant for infective endocarditis, compared with capsular cells and the acapsular cells facilitated the incorporation of capsular cells to the biofilm formed by acapsular cells.