USE OF ENZYME-LINKED IMMUNOASSAYS FOR ANTIBODY TO TYPE-C AND TYPE-D BOTULINUM TOXINS FOR INVESTIGATIONS OF BOTULISM IN CATTLE

The development of specific enzyme-linked immunosorbent assays (ELISA) for antibody to types C and D Clostridium botulinum toxins for invest igation of botulism in cattle is described. Partially purified type C and D toxins were used as antigens to develop these ELISAs. Specificit y of the ELISAs was evaluated on sera from 333 adult beef and dairy ca ttle from areas with no history or evidence of botulism in animals or water birds. The test was also evaluated on sera from 41 herds that in cluded herds vaccinated against botulism, confirmed botulism cases and herds from areas where the disease is considered endemic. The ELISAs detected the presence of antibody to botulinum toxins in samples from vaccinated cattle and both convalescent and clinically normal animals from unvaccinated herds with outbreaks of botulism, Antibody was also found in unvaccinated animals from herds in which there had been no di agnosed botulism cases in areas where botulism was considered endemic. Sera from some unvaccinated cattle with high ELISA reactivity was sho wn to be protective for mice in botulinum toxin neutralisation tests. The use of these tests in investigations of botulism in cattle is disc ussed.