The structure of the capsular polysaccharide from a swarming strain of pathogenic Proteus vulgaris

The structure was determined for the capsular polysaccharide (CPS) isolated from a swarming strain of Proteus vulgaris, CP2-96, which was obtained from the spleen of an infected mouse. The CPS was extracted from the cell pellet by hot water, precipitated with ethanol, and further purified by gel-permeation chromatography. The structure was established by glycosyl composition and linkage analyses, and by NMR spectroscopy. The sequence of the glycosyl residues was determined by a NOESY experiment. The CPS is composed of a tetrasaccharide repeating unit with the following structure: