Immunochemistry of the cell-surface carbohydrate antigens of Clostridium difficile.

Two carbohydrate cell-surface antigens were extracted from Clostridium difficile. One was extracted from pure cell walls by NaOH and contained glucose, mannose, galactosamine and phosphate in the approximate molar proportions of 2:0.65:1:0.63. The other antigen was extracted with phenol from the disrupted contents of whole cells and purified by chromatography on Sepharose 6B and an immunoabsorbent column; it contained glucose, glucosamine, phosphate and fatty acid in the approximate molar proportions of 2:1:1.6:0.04. Both antigens showed partial immunological identity and both cross-reacted with Clostridium sordellii antiserum. They are analogues of the wall and membrane teichoic acids of other Gram-positive bacteria.