All acidic carbohydrate has been isolated from the culture medium of the enteric microorganism E. coli K235 L+O. This substance has been named colominic acid.
N-acetylneuraminic acid, which has been isolated from the hydrolysate of colominic acid, is believed to be the monomer unit from which colominic acid is constituted.
Colominic acid is not antigenic in rabbits. Tests have failed to reveal a relationship between the ability of E. coli K235 to elaborate colominic acid and its virulence in mice.