Abstract: 　Objective To find out the specific diagnostic antigens in excretory-secretory (ES) products from muscle larvae of Trichinella spiralis. Methods The ES antigens (ESA) of Trichinella spiralis muscle larvae cultured in vitro at 18 h and 30 h were analyzed by SDS-PAGE and Western blotting. Results At different times after cultivation, the protein components of ESA of T. spiralis muscle larvae were similar. SDS-PAGE revealed that the molecular weight(MW) of the major bands of 2 ES antigens were 112, 110, 108, 97, 53, 49, 45, 42, 35, 23 and 16 kDa. Western blotting showed that the protein bands with 102, 97, 95 and 53 kDa in 18 h ESA and the protein bands with 53, 49, 45 and 43 kDa in 30 h ESA cross-reacted with sera from the patients with paragonimiasis, clonorchiasis, schistosomiasis, and cysticercosis, respectively. The protein component with 23 kDa in ESA only reacted with sera from the rats and mice infected with T. spiralis and the patients with trichinellosis, but not reacted with sera from animals and patients infected with other parasites, and sera from normal rats, mice and persons. Conclusion The protein component with 23 kDa in T. spiralis ESA is the specific antigen of T. spiralis muscle larvae and it could be applied to the serodiagnosis and seroepidemiological survey of trichinellosis.

Key words: Trichinella spiralis, muscle larva, excretory-secretory antigen(ESA), SDS-PAGE, Western blotting