The capsular polysaccharide (CPS) of Streptococcus suis serotype 14 was purified, chemically modified, and characterized. Sugar and absolute configuration analyses gave the following CPS composition: D-Gal, 3; D-Glc, 1; D-GlcNAc, 1; D-Neu5Ac, 1. The Sambucus nigra lectin, which recognizes the Neu5Ac(α2-6)Gal/GalNAc sequence, showed binding to the native CPS. Sialic acid was found to be terminal, and the CPS was quantitatively desialylated by mild acid hydrolysis. It was also submitted to periodate oxidation followed by borohydride reduction and Smith degradation. Sugar and methylation analyses, (1)H and (13)C nuclear magnetic resonance, and mass spectrometry of the native CPS or of its specifically modified products allowed to determine the repeating unit sequence: [6)[Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-3)]Gal(β1-3)Gal(β1-4)Glc(β1 -](n). S. suis serotype 14 CPS has an identical sialic acid-containing side chain as serotype 2 CPS, but differs by the absence of rhamnose in its composition. The same side chain is also present in group B Streptococcus type Ia CPS, except that in the latter sialic acid is 2,3- rather than 2,6-linked to the following galactose. A correlation between the S. suis CPS sequence and genes of the serotype 14 cps locus encoding putative glycosyltransferases and polymerase responsible for the biosynthesis of the repeating unit is proposed.
chemical modification, nuclear magnetic resonance (NMR), mass spectrometry (MS), repeating unit sequence, Streptococcus suis serotype 14
NCBI PubMed ID: 23527632Publication DOI: 10.1139/bcb-2012-0036Journal NLM ID: 8606068Publisher: Ottawa: National Research Council of Canada
Correspondence: marie-rose.vancalsteren@agr.gc.ca
Institutions: Groupe de recherche sur les maladies infectieuses du porc (GREMIP) and Centre de recherche en infectiologie porcine (CRIP), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, QC J2S 2M2, Canada, Food Research and Development Centre, Agriculture and Agri-Food Canada, Saint-Hyacinthe, QC J2S 8E3, Canada, Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan
Methods: 13C NMR, 1H NMR, NMR-2D, GC-MS, sugar analysis, ESI-MS, mild acid hydrolysis, Smith degradation, NMR-1D, methanolysis
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