Inhibition of the Interaction Between Fimbrial Haemagglutinins and Erythrocytes by D-Mannose and Other Carbohydrates

Abstract

SUMMARY Many monosaccharides, oligosaccharides and their derivatives were tested as inhibitors of agglutination of guinea-pig or horse erythrocytes by Salmonella typhiinurium or Shigella flexneri bacteria bearing type- I fimbriae. D-Mannose and certain derivatives of mannose were strongly inhibitory, and D-fructose moderately inhibitory. Modification of any of the hydroxyl groups at the (2-2, C-3, C-4 or C-6 positions in the D-mannopyranosyl molecule caused failure to inhibit, showing that these groups were necessary for binding to the active sites of the fimbrial haemagglutinin. The a-configuration at the C-I position in D-mannose was impor- tant and carbohydrates containing a-linked D-mannose were much more active inhibitors than those containing P-linked D-mannose, which were poor inhibitors or non-inhibitors. Yeast mannan also inhibited the fimbrial reaction. Attention is drawn to the remarkable degree of similarity of the inhibition pattern of the type-r fimbrial haernagglutinin of bacteria with that of concanavalin-A, the jack bean haemagglutinin.