Detection of Clostridium botulinum type B toxin in the presence of a lethal substance interfering with toxin neutralization.

A low molecular weight substance that induced seizures and death in mice was present in the stool of a child with infant botulism. This interfered with mouse bioassay used for detecting Clostridium botulinum toxin. After removal of the interfering substance by a prolonged dialysis with buffered saline, in vivo neutralization of botulinal toxin was readily achieved. Alternatively, the botulinal toxin was demonstrated in stool of the infant by an enzyme-linked immunosorbent assay (ELISA), using antibodies produced in immunologically tolerant rabbits.