Abstract: Objective To analyze antigens for searching specific antigenic components for immunodiagnosis of echinococcosis. MethodsFourteen crude antigens from different tissues (cyst fluid, protoscoleces, laminated layer and germinal layer) of Echinococcus granulosus and E.multilocularis metacestodes and other 4 species of cestodes were analyzed by Western blotting. The differences of protein bands were compared for the 14 crude antigens by reacting with pooled sera from cystic echinococcosis (CE) and alveolar echinococcosis (AE) patients. Results Eleven protein bands from the antigens reacted nonspecifically with sera from both CE and AE patients were Mr 130 000, {100 000, 94 000, 80 000, 75 000, 66 000, 62 000, 52 000, 38 000, 32 000, 24 000. The highly specific protein bands recognized by AE sera were Mr 120 000, 109 000, 86 000, 59 000, 43 000, 8 000, 20 000, 18 000, and by CE sera were Mr 41 000, 40 000, 22 000, 16 000 and 12 000 Conclusion Different antigens shared by the two species of Echinococcus were examined and potential antigenic proteins specific for AE or CE sera were found, providing useful information for further identifying specific antigens for immunodiagnosis.

Key words: Echinococcus metacestodes, antigen, Western blotting