CRYPTOSPORIDIUM-PARVUM OOCYST ANTIGENS RECOGNIZED BY SERA FROM INFECTED ASYMPTOMATIC ADULT CATTLE

Gel electrophoresis and Western blotting were used to investigate the recognition ofCryptosporidium parvum oocyst antigens by sera from asym ptomatic C. parvum-seropositive cattle with or without coccidian oocys ts in their faeces (C. parvum or/and Eimeria spp.). Most sera from cop rologically C. parvum-positive animals (71%) recognized fractions in t he 17-20 kDa range; these fractions were not recognized by sera from c oprologically negative animals. In addition, most sera with antibodies to C, parvum (whether from coprologically positive or negative animal s) showed moderate or strong reaction with antigenic fractions in the 47-49.5 kDa range (43%) and the 56.5-69 kDa range (80%).