2000 Volume 62 Issue 11 Pages 1231-1234
Antibodies against Cryptosporidium parvum in the saliva and sera of three calves experimentally infected with this parasite were examined by an indirect immunofluorescence antibody test and immunoblotting.Salivary anti−C.parvum IgA antibody appeared on day 12 post−challenge and had a tendency to increase transiently between days 15 and 30 post−challenge.Salivary anti−C.parvum IgG antibody levels showed a gradual increase along with the change in IgA antibody levels during the infection.In contrast, serum anti−C.parvum IgA antibody levels showed only a slight increase between days 15 and 30 post−challenge.Serum anti−C.parvum IgG antibody levels rose on day 12 post−challenge and one calf maintained relatively high level up to the end of the experiment.In immunoblotting, an antigen with a molecular mass of 15 kDa was found to react strongly to salivary IgA antibody and a 27 kDa antigen to react to serum IgG antibody.