人体带绦虫的分子鉴定

Molecular Identification of Human Taenia Tapeworms

目的:对采自云南大理的6条人体带绦虫进行虫种分子鉴定。方法:对云南省大理有排节片史的病人以槟榔-南瓜子法驱虫,对6条人体带绦虫成虫进行形态学鉴定;提取虫体基因组DNA,用亚洲带绦虫和牛带绦虫线粒体cox1基因片段的特异性引物对DNA进行常规PCR扩增,扩增产物经琼脂糖凝胶电泳检测;将虫卵喂食2头幼猪(5×105/头),40 d后解剖检查.观察囊尾蚴寄生情况。结果:6条人体带绦虫的形态和牛带绦虫相似,亚洲带绦虫cox1片段PCR为阳性,扩增产物约260 bp,牛带绦虫cox1片段PCR均为阴性;只在感染幼猪肝脏发现有囊尾蚴寄生,其他组织和肌肉内没有囊尾蚴寄生。结论:形态学和分子生物学鉴定6条人体带绦虫标本均属于亚洲带绦虫。

Objective： To identify the species of 6 human Taenia tapeworms in Dali of Yunnan prov- ince. Methods： Six Taenia tapeworms were expelled and collected from patients with proglottids in stool by using betel nut - pumpkin seed method in Dali of Yunnan province. Morphological identifica- tion was carried out on the 6 adult Taenia tapeworms. Genomic DNA of the 6 worms was extracted, and specific primers of mitochondrial coxl gene fragments of Taenia asiatica and Taenia saginata were used to amplify DNA with conventional PCR, and the products were confirmed by agarose gel electro- phoresis. Two pigs were fed with eggs of the worms （5 ~ l0s per pig）. Anatomical examination was performed on the 40th day. Cysticercus parasitizing situation were observed. Results： The morphology of 6 Taenia tapeworms was similar to T. saginata. The PCR products using T. asiatica fragments as primers were positive in electrophoresis and were about 260 bp. All samples using T. saginata frag- ments as primers were negative in electrophoresis. Cysticercus was found in livers of the infected pigs rather than in other tissues and muscle. Conclusions： Morphological and molecular classification shows that the 6 Taenia tapeworms are T. asiatica.