Structure of the O-antigen of a novel Shigella flexneri serotype, 1d (I: 7,8)

•A novel Shigella flexneri serotype, 1d (I: 7,8), was discovered in China.•The O-polysaccharide structure of 1d was established by NMR spectroscopy.•A serologically identical strain, 036_1d, was constructed from serotype Y.•The construct was demonstrated to possess the same O-polysaccharide structure.

Recently, strains of a novel Shigella flexneri serotype called 1d have been isolated from diarrheal patients in China. They are distinguished by the presence of a hitherto unknown combination of type O-factor I and group O-factor 7,8, both associated with lateral α-d-glucosyl groups on the basal linear O-polysaccharide. A serologically identical strain, 036_1d, has been constructed in the laboratory by sequential infection of serotype Y by serotype-converting bacteriophages SfX and SfI. In this work, using 1D and 2D 1H and 13C NMR spectroscopy, we established the following structure of the O-antigen of S. flexneri serotype 1d and demonstrated that the O-antigen of the 036_1d construct has the same structure:Figure optionsDownload full-size imageDownload as PowerPoint slide

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