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, dotblotting 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 postinfection 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.