Effect of the glycosyltransferases on the capsular polysaccharide synthesis of Streptococcus suis serotype 2

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• 作者：Yanyan Zhang^a ; ^c ; ^d ; Dandan Ding^a ; ^c ; ^d ; Manli Liu^b ; Xiaopei Yang^a ; ^c ; ^d ; Bingbing Zong^a ; ^c ; ^d ; Xiangru Wang^a ; ^c ; ^d ; Huanchun Chen^a ; ^c ; ^d ; Weicheng Bei^a ; ^c ; ^d ; Chen Tan^a ; ^c ; ^d ; ^{tanchen@mail.hzau.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Streptococcus suis serotype 2 ; S. suis 2 SC19 ; Capsular polysaccharide ; cps2E/cps2G/cps2J/cps2L ; Virulence
• 刊名：Microbiological Research
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：185
• 期：Complete
• 页码：45-54
• 全文大小：2177 K

文摘

Streptococcus suis serotype 2 (S. suis 2) is a serious zoonotic pathogen causing septicemia and meningitis in piglets and humans. The capsular polysaccharide (CPS) is an essential virulence factor for S. suis 2 to infect the host. The synthesis of CPS repeating units involves multiple glycosyltransferases. In this study, four genes (cps2E, cps2G, cps2J and cps2L) encoding different glycosyltransferases involved in CPS synthesis were researched in S. suis 2. Four deletion mutants (Δcps2E, Δcps2G, Δcps2J and Δcps2L) with their CPS incomplete and their sialic acid content significantly decreased were constructed in S. suis 2 SC19. All these four mutant strains showed enhanced adhesion to Hep-2 cells and increased sensitivity to phagocytosis. Flow cytometric analysis also revealed that these four mutants were more susceptible to the attack by the complement system. In a mouse model of infection, the mutant strains were rapidly cleared by the immune system, compared with the wild-type strain. In summary, this study characterized four genes (cps2E, cps2G, cps2J and cps2L) involved in CPS synthesis of S. suis 2 SC19 and it revealed that these genes were all crucial for SC19 to invade and survive in the host.