The aim of the
present study was to analyze the antibody response against excretory-secretory
antigens (ES-Ag) from Echinococcus
sera from dogs infected with E. granulosus
and other helminths.
ES-Ag were obtained from the first 50 h maintenance of protoscoleces in
vitro. Immunochemical characterization was performed by immunoblotting
with sera from dogs naturally infected with E. granulosus
(n = 12),
sera from dogs infected with helminths other than E. granulosus
= 30), and helminth-free dog sera (n = 20). These findings were compared
to those obtained from a somatic extract of protoscoleces (S-Ag). ES-Ag
only showed four cross-reacting proteins of 65, 61, 54, and 45-46 kDa.
Antigens with apparent masses of 89 and 50 kDa in ES-Ag and of 130 and
67 kDa in S-Ag were identified by sera of dogs infected with E. granulosus
whereas a protein of 41-43 kDa was recognised by the majority of the sera
from dogs with non-echinococcal infection. Employing ELISA to study the
same sera, S-Ag revealed higher immunoreactivity than ES-Ag, but also showed
higher cross-reactivity levels when sera from dogs with non-echinococcal
infection were assayed in immunoblotting.