Abstract

The polysaccharide part of the lipopolysaccharide isolated from an enteroaggregative Escherichia coli isolated from a young child with diarrhoea in Santiago, Chile (strain 17-2), has been investigated. Sugar and methylation analyses of native and partially degraded polysaccharide together with H-1-NMR and C-13-NMR spectroscopies revealed that the polysaccharide is composed of pentasaccharide repeating units. The structure of the repeating unit of E. coli strain 17-2 O-polysaccharide is: [GRAPHICS] The structure of the O-polysaccharide from E. coli O3 was shown to be identical to that of E. coli strain 17-2 by sugar and methylation analyses and by H-1-NMR and C-13-NMR spectroscopies.