Chemical Comparison of the Polysaccharide Portions of Shigella Lipopolysaccharides and Their Relation to Virulence.
Annual summary rept. 1 Mar 73-30 Jun 74,
LUTHER COLL DECORAH IOWA
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Lipopolysaccharides LPS were extracted from virulent and avirulent strains of Shigella flexneri 2a, S. flexneri 1b, S. sonnei, and E. coli - S. flexneri hybrids in an effort to determine if the difference in virulence could be explained by chemical differences in the polysaccharide portion of the lipopolysaccharides. Comparison of the monosaccharide content of LPS from virulent and avirulent strains showed no major differences in the chemical content of this portion of the LPS which could explain their difference in virulence. However, comparison of the monosaccharide content of LPS from organisms grown on Brain-Heart Infusion BHI agar with that from organisms grown in BHI broth showed a five fold increase in the length of the O side chains of both virulent and avirulent agar grown cells. The polysaccharide component of the LPS is essentially identical in both the virulent and avirulent organisms studied. Modified author abstract