Abstract:

【Objective】 To investigate the recombinant CE18 (Cystic Echinococcosis protein 18 kD) antigen for immunodiagnosis of metacestode diseases in sheep. 【Method】 A total of 259 sera samples from sheep infected with larval stage Taenia multiceps (Tm, 18), T. hydatigena (Th, 15) or Echinococcus granulosus (Eg,19), and sheep from an epidemic area of echinococcosis (194) and normal sheep (control, 13) were examined by enzyme-linked immunosorbent assay (ELISA) to detect the antibodies against the rCE18 protein. The significant difference method was used to evaluate the values of rCE18 protein as an antigen for diagnosis of cestode-larva diseases in sheep. Analysis of rCE18 protein from different species was performed using biological softwares. 【Result】 Similarities of homologous CE18 protein among different taeniid genera were up to 99% at amino acid level. The sero-positive rate of rCE18-ELISA was 38.89% in Tm, 73.33% in Th, 100% in Eg, and 76.14% in the epidemic area of echinococcosis, respectively, whereas that of the healthy control was negative. 【Conclusion】 CE18 protein may be a useful antigen for the immunodiagnosis of sheep infected with the larva of cestodes, especially for Eg and/or Th.

Key words: recombinant CE18 protein, ovine, metacestodiasis, antibody, immunodiagnosis