重组CE18蛋白在绵羊绦虫蚴病诊断上的应用

Application of Recombinant CE18 Protein for Diagnosis of Ovine Metacestodiasis

【目的】探讨细粒棘球蚴CE18重组蛋白作为绦虫蚴病免疫诊断抗原的应用价值,为筛选绦虫蚴病血清学诊断抗原提供依据。【方法】应用棘球蚴CE18重组抗原建立间接ELISA方法,分别对18份脑多头蚴、15份细颈囊尾蚴、19份棘球蚴感染绵羊血清及194份棘球蚴病疫区绵羊血清和13份健康羊血清进行检测,通过显著性差异分析评价CE18蛋白作为诊断抗原的意义。同时,应用生物学软件对CE18抗原蛋白同源序列进行分析,进一步从分子水平上提示CE18蛋白作为绦虫蚴病诊断抗原的依据。【结果】序列分析表明棘球蚴CE18蛋白基因为多种绦虫如泡状带绦虫、多头带绦虫、猪带绦虫等的共有序列,其蛋白质氨基酸序列相似性很高,不同种属之间高达99%,从分子水平上表明CE18蛋白为带绦虫蚴共同抗原成分之一。重组抗原CE18-ELISA方法检测绵羊血清抗体水平显示:脑多头蚴病、细颈囊尾蚴病、棘球蚴病和棘球蚴病疫区血清的阳性率分别为38.89%、73.33%、100%和76.14%,而对照组血清为阴性反应。【结论】CE18重组蛋白可作为绵羊棘球蚴病和细颈囊尾蚴病血清学诊断抗原,用于畜群活体检疫初筛试验。

[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 094） 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.