Vinogradov Evgueny, Goyette-Desjardins Guillaume, Okura Masatoshi, Takamatsu Daisuke, Gottschalk Marcelo, Segura Mariela
National Research Council, Ottawa, Ontario, Canada.
Laboratory of Immunology, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada.
Carbohydr Res. 2016 Oct 4;433:25-30. doi: 10.1016/j.carres.2016.07.005. Epub 2016 Jul 5.
Streptococcus suis serotype 9 is the most prevalent S. suis serotype in several European countries. In spite of its pathogenicity for pigs and increasing zoonotic potential, limited information is available on this serotype. Here we determined for the first time the chemical composition and structure of serotype 9 capsular polysaccharide (CPS), a major bacterial virulence factor and the antigen at the origin of S. suis classification into serotypes. Chemical and spectroscopic data gave the repeating unit sequence: [3)Glcol-6-P-3-[D-Gal(α1-2)]D-Gal(β1-3)D-Sug(β1-3)L-Rha(α1-)]n. Compared to previously characterized S. suis CPSs (serotypes 1, 1/2, 2 and 14), serotype 9 CPS does not contain sialic acid but contains a labile 4-keto sugar (2-acetamido-2,6-dideoxy-β-D-xylo-hexopyranos-4-ulose), one particular feature of this serotype. A correlation between S. suis serotype 9 CPS sequence and genes of this serotype cps locus encoding putative glycosyltransferases and polymerase responsible for the biosynthesis of the repeating unit was tentatively established. Knowledge of CPS structure and composition will contribute to better dissect the role of this bacterial component in the pathogenesis of S. suis serotype 9.
猪链球菌9型是几个欧洲国家中最常见的猪链球菌血清型。尽管它对猪具有致病性且人畜共患病潜力不断增加，但关于该血清型的信息有限。在此，我们首次确定了9型荚膜多糖（CPS）的化学组成和结构，CPS是一种主要的细菌毒力因子，也是猪链球菌血清型分类的抗原来源。化学和光谱数据给出了重复单元序列：[3)Glcol-6-P-3-[D-Gal(α1-2)]D-Gal(β1-3)D-Sug(β1-3)L-Rha(α1-)]n。与先前已鉴定的猪链球菌CPSs（血清型1、1/2、2和14）相比，9型CPS不含唾液酸，但含有一种不稳定的4-酮糖（2-乙酰氨基-2,6-二脱氧-β-D-木糖己吡喃糖-4-酮），这是该血清型的一个特殊特征。初步建立了猪链球菌9型CPS序列与该血清型cps基因座中编码负责重复单元生物合成的假定糖基转移酶和聚合酶的基因之间的相关性。对CPS结构和组成的了解将有助于更好地剖析这种细菌成分在猪链球菌9型发病机制中的作用。
