Me. Ares-mazas et al., Oocysts, IgG levels and immunoblot patterns determined for Cryptosporidiumparvum in bovine examined during a visit to a farm (northeastern Spain), VET PARASIT, 81(3), 1999, pp. 185-193
Single fecal and serum samples were individually collected from 101 bovines
selected at random during a visit to a farm in northeastern Spain (Group I
, 26 animals aged 2-36 days; Group II, 34 animals aged 1.5-4.5 months; Grou
p III, 41 animals aged 20-24 months). Testing for the presence of Cryptospo
ridium parvum oocysts in feces (Monofluo Kit Cryptosporidium, Diagnostics p
asteur, France) indicated that 26% animals were infected (81% of Group I, 1
5% of Group II and 0% of Group III). Serological testing (ELISA for detecti
on of specific anti-C, parvum IgG) indicated that 59% animals were seroposi
tive (12% of Group I, 74% of Group II and 78% of Group III). Immunoblotting
results indicate that cattle sera recognize C. parvum antigens of widely v
arying molecular weights and that the number of antigens recognized increas
es with age. Immunoblots revealed that some of the sera belonging to the Gr
oup I reacted with protein fractions between 15 and 20 kDa but none recogni
zed the 21-23 kDa antigen. Only few sera in the Group II recognized the pro
tein fraction between 15 and 20 kDa. The recognition of 21-23 kDa fraction
was observed by four sera from uninfected and seropositive animals. Sera fr
om all the seronegative Group II animals recognized few antigens and always
with molecular weight greater than 50 kDa. Serum samples from both seropos
itive and seronegative animals belonging to the Group III recognized antige
ns with molecular weight ranging 15-20 kDa. Surprisingly, the protein fract
ions between 21 and 28 kDa reacted with approximately 30% of the sera from
seropositive animals and only one of the nine sera from seronegative animal
s. The recognition of 42-46 kDa antigens increased with the age and only re
acted with the sera from uninfected animals. (C) 1999 Elsevier Science B.V.
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