Abstract: Objective Objective To develop a quick and easy colloidal gold immunochromatography assay （GICA）strip for schistoso? miasis diagnosis in domestic animals. Methods Methods The reconstruction of Streptococcal Protein G（SPG）was designed and its gene was subcloned into plasmid pET?28a （+）to express in Escherichia coli. The recombinant SPG was purified and labeled with colloidal gold. The Schistosoma japonicum soluble egg antigen（SEA）and rSPG were blotted on the nitrocellulose membrane for the test line and control line respectively. The specificity，sensitivity and cross?reaction of the strip method were detected. Re Re? ? sults sults The rSPG was successfully expressed and purified to label with colloidal gold. The colloidal gold immunochromatography assay strips were assembled and they could detect the sera of S. japonicum infected BALB/c mice，New Zealand white rabbits， buffalo and sheep successfully. Besides，the sensitivity of GICA strip was 100% in the sera of mice and the serum of rabbits with S. japonicum infection. The specificity was 100% in the serum of mice and the sera of rabbits with free of infection. The sensitivi? ty was 100% in the sera of sheep with miracidia of S. japonicum hatching from the stool and the specificity was 88.46% in the se? ra of sheep without that. The sensitivity was 94.44% in the sera of buffalo with miracidia hatching from the stool and the specifici? ty was 100% in the sera of buffalo without that. The cross?reaction rate was 5.88% in Paramphistomum. Conclusion Conclusion The GICA strip can successfully detect a variety of S. japonicum infected domestic animals and may be a useful tool for screening on a large scale in the endemic areas.

Key words: Schistosomiasis；Colloidal gold immunochromatography assay strip；Immunodiagnosis；Domestic animal；Re? combinant Streptococcal Protein G

摘要： 目的 目的 研制一种可用于疫区现场快速诊断家畜日本血吸虫感染的胶体金免疫层析试纸条。方法 方法 设计重组蛋 白G并在大肠杆菌中表达， 得到重组蛋白。对重组蛋白G进行胶体金标记并制备金标垫， 分别用可溶性虫卵抗原 （SEA） 和重组蛋白G划线， 作为检测线和质控线。采用组装的试纸条检测标准阴、 阳性BALB/c鼠与新西兰大白兔血清， 以及粪 检阴、 阳性的绵羊与水牛血清， 评估其灵敏度和特异度； 利用组装的试纸条检测前后盘吸虫病病牛血清， 评价其交叉反应 性。结果 结果 成功构建了重组蛋白G的原核表达质粒并在大肠杆菌中表达。以重组蛋白G制备的试纸条可用于检测日本 血吸虫感染BALB/c鼠、 新西兰大白兔、 水牛、 绵羊血清抗体。该试纸条检测日本血吸虫感染小鼠与兔血清的灵敏度、 特 异度均为100%； 检测绵羊血清的灵敏度为100%， 特异度为88.46%； 检测水牛血清的灵敏度为94.44%， 特异度为100%； 其与前后盘吸虫交叉反应率为5.88%。结论 结论 成功研制能检测多种家畜血吸虫病的胶体金免疫层析试纸条， 其检测家 畜血吸虫感染的灵敏度和特异度均较高。

关键词: 日本血吸虫病； 胶体金免疫层析试纸条； 免疫诊断； 家畜； 重组蛋白G