Scientific Publications by FDA Staff

J Bacteriol 2014 Sep 15;196(18):3271-8

Chemical Structure of the Capsular Polysaccharides (CPS) of Streptococcus pneumoniae Types 39, 47F and 34 by NMR Spectroscopy and their Relation to CPS10A.

Bush CA, Yang J, Yu B, Cisar JO

Structural characterization of Streptococcus pneumoniae capsular polysaccharides (CPS) is a prerequisite for unraveling antigenic as well as genetic relationships that exist between different serotypes. In the current study, comparative structural studies of S. pneumoniae CPS serogroup 10 were extended to include genetically related S. pneumoniae CPS34, 39 and 47F. High-resolution hetero-nuclear NMR spectroscopy confirmed the published structure of CPS34 and in conjunction with glycosyl composition analyses, revealed repeat unit structures of the other serotypes, which have not been previously characterized: jb;JB.01731-14v1/FU1F1FU1 Common and unique structural features of these polysaccharides, including different positions of O-acetylation, were unambiguously associated with specific genes in each corresponding cps locus. The only exception involved the gene designated wcrC, which is associated with the alpha1-2 transfer of Galp to ribitol-5-phosphate in synthesis of CPS10A, CPS47F and CPS34 but alpha1-1 transfer of Gal to ribitol-5-phosphate in CPS39. The corresponding gene in the cps39 locus, although related to wcrC, more closely resembled a previously identified gene (i.e. wefM) of S. oralis associated with alpha1-1 transfer of Galp to ribitol-5-phosphate. These and other recent findings identify linkages from alpha-Galp to ribitol-5-phosphate and from this residue to adjacent Galf as important sites of CPS structural and genetic diversity.