Untersuchungen zur Antigenstruktur von Shigellen Heterogenität der spezifischen Polysaccharide von zwei Shigella flexneri‐Stämmen und zwei Sh. flexneri/Escherichia coli‐Hybriden

Abstract

The S-specific polysaccharide from 2 Sh. flexneri wild strains (with serological var. Xand var. Y-specificity, respectively) and 2 Sh. jlexneri E . coli hybrids (with the same specificities) can be separated by means of gel chromatography on Sephadex G-200 and G-50 into altogether 6 fractions per strain. Fraction 6-200/1 (molecular weight > 10OD) represents a polymer consisting nearly exclusively of glucose and is present mainly in the two Y-type strains, much less in the two Xtype strains. Fractions G-200/2 and G-200/3 (molecular weight -106D and -2 * lo4 D, respectively) seem to consist mainly of the S-specific side chains while fraction G-50/2 (molecular weight -2000 D) presumably contains an SR-polysaccharide (core with one repeating unit). Fraction G-50/3 (molecular weight -1000 D) contains the core polysaccharide and fraction G-50/4 splitting products (mainly KDO). No significant differences in chromatographical behaviour and quantitative composition could be found between the polysaccharides of the wild strains and the hybrid strains.Because of the well-known stability of the glucosaminyl linkages the sugar analysis was not only performed after acidic hydrolysis. I n some cases the acid hydrolysate was reacted with HNO, to cleave the glucosaminyl linkages. I n most cases the values obtained now were higher than those obtained directly. 27'