Evaluation of Echinococcus granulosus coproantigens by Dot-blotting in dogs

Definitive hosts of the Echinococcus granulosus (E. granulosus) parasite are carnivores such as dogs, wolves and foxes. Detection of this parasite through faecal examination is not possible. In this study, dot-blotting test for E. granulosus-specific coproantigens has been evaluated in dog. Three 2–3-month-old puppies were treated with piperazine and then faecal samples were collected as pre-infection samples. Seven days later, hydatid cysts from livers and lungs of sheep were fed to the puppies. Faecal samples were collected weekly for five weeks as post-infection samples. Soluble protein of pre- and post-infection faecal samples were prepared and dot-blotting test was conducted. In parallel experiments, the presence of E. granulosus eggs and also dot-blotting test were evaluated in 15 faecal samples of dogs collected from Razi Veterinary Hospital in Mashhad. For the detection of protein bands in pre-infection and fifth-week post-infection samples, polypeptide profile was analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that incremental spot colours was observed in samples of experimentally infected dogs collected from the first to fifth post-infection weeks. In dot-blot analysis of faecal samples in 15 dogs, 4 samples were positive, and also these four samples were positive for E. granulosus eggs. In SDS-PAGE, one band in pre-infection and four bands in fifth-week post-infection samples were observed. The molecular weight of pre-infection sample of experimentally infected dogs was 16 kDa and the molecular weights of the samples collected five weeks post-infection were 14, 22, 36 and 45 kDa, respectively. In conclusion, the results of this experiment showed that the dot-blotting method does not produce a reliable outcome. For evaluation of the specific coproantigens of E. granulosus in dogs, coproantigen-ELISA test is needed.