Immunochemistry of Salmonella O-antigens: studies of Salmonella BO antigen epitopes by enzyme-linked immunosorbent inhibition assays

The binding of Salmonella</it> serogroup B O</it>-polysaccharide to a rabbit BO antiserum was studied with ELISA inhibition. Synthetic di-, tri- and tetrasaccharide fragments of the O</it>-polysaccharide carrying structural alterations at specific positions were used as inhibitors. Structural alteration in the O2–O4 region of the abequose residue resulted in loss of binding capacity, whereas the O6 of the mannosyl residue could be replaced with hydrogen without significant reduction in binding by the antiserum. Other structural features in the mannosyl residue were, however, shown to be important for binding. The rhamnosyl O1 region also played a role in the binding process.