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Updated: Apr 23, 2026

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction
Published on: February 24, 2014
[Comparison of monosaccharide composition of capsular polysaccharides in Streptococcus suis serotype 1, 2, 14 and
Objective:
There are one-way or two-way cross-reactions among Streptococcus suis serotype 1, 2, 1/2 and 14, the reason to which was unknown.
Methods:
The capsular polysaccharides of serotype 14 and 1/2 were purified on Sephacryl S-300 column and identified by phenol-sulphuric acid method and dot-ELISA. The molecular weight of the serotype 14 and 1/2 capsular polysaccharides was revealed as 487.38 kDa and 512.72 kDa by high performance gel permeation chromatography, respectively.
Results:
The monosaccharide composition of serotype 14 and 1/2 capsular polysaccharides was determined as Glc/Gal/GlcNAc/Rha/Neu5Ac (1: 2.94 : 1.35 : 0.24 : 0.37) and Glc/Gal/GlcNAc/GalNAc/Rha/Neu5Ac (1 : 1.67 : 1.05 : 0.93: 0.72 : 0.7) by pre-column derivatization high performance liquid chromatography, fluorescent labeling HPLC and NMR, respectively. These were compared with the composition of serotype 1 and 2 capsular polysaccharides. Glc, GlcN, Gal and Neu5Ac was contained in the capsular polysaccharides of serotype 1, 2 14 and 1/2. But there is no prominent correlation between the monosaccharide composition and cross-reactions. The cross-reactions among them could be induced by the structure of the capsular polysaccharides and/or the other components on the cell wall.
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