Echinococcus multilocularis: Two-dimensional Western blotting method for the identification and expression analysis of immunogenic proteins in infected dogs

Domesticated dogs are an important potential source of Echinococcus multilocularis infection in humans; therefore, new molecular approaches for the prevention of the parasite infection in dogs need to be developed. Here, we identified and characterized an immunogenic protein of the parasite by using a proteome-based approach. The total protein extracted from protoscoleces was subjected to two-dimensional Western blotting with sera from dogs experimentally infected with E. multilocularis. Two protein spots showed major reactivity to the sera from infected dogs. The N-terminal amino acid sequences of these spots were identical to the deduced amino acid sequence of the product of the putative hsp20 gene. RT-PCR and Western blot analyses revealed that the putative hsp20 gene and its products were expressed in almost all stages of the parasite life cycle. Furthermore, recombinant hsp20 showed specific reactivity to the sera from infected dogs, suggesting that this molecule may facilitate the development of a practical vaccine.