> Echinococcus granulosus is the causative agent of hydatid disease in humans and animals. Natural transmission of the parasite occurs between dogs as definitive hosts and animal intermediate hosts. There is an urgent need for improved methods to control the parasite's transmission. Here we describe the development of a vaccine based on a cloned recombinant antigen from the parasite egg (oncosphere). Sheep vaccinated with the antigen, designated EG95, are protected (mean 96–98%) against hydatidosis developing from an experimental challenge infection with E. granulosus eggs. The vaccine will provide a valuable new tool to aid in control of transmission of this important human pathogen. It also has the potential to prevent hydatid disease directly through vaccination of humans.

This study was designed to develop an indirect ELISA for detection of sheep antibodies against Echinococcosis granulosa, which will provide a fast and simple means for detection Echinococcosis granulosa of sheep. The amino acid sequences of EG95 published in GenBank were analyzed using DNAStar software, and the hydrophilic epitopes were selected, named EG95s. Then the gene of EG95s were cloned and expressed. As a result, an indirect ELISA for detection of sheep antibodies against Echinococcosis granulosa were developed using the purified recombinant fusion protein as the coating antigen, therefore a variety of conditions were optimized. The results of SDS-PAGE showed that the recombinant fusion protein, GST-1EG95s and HIS1EG95s, were efficiently expressed, which were soluble and purified easily Then the results of Western blot showed that the expression products were reacted with positive serum of sheep with Echinococcosis granulosa, which indicated they were good immunogenicity. The optimized conditions of indirect ELISA showed that: HIS-1EG95s was better than GST-1EG95s as the coating antigen. The determine criteria of the indirect ELISA were: Samples with an OD450 nm value ≥ 0.235 were judged as positive, and with an OD450 nm value≤ 0.191 were judged as negative, while with an OD450 nm value ranging between them was suspicious. 70 positive and negative serum of sheep collected in Xinjiang with or without Echinococcosis granulosa were detected by the indirect ELISA respectively, and the results showed that this indirect ELISA method was completely consistent with the indirect ELISA provided by Wallaceville Animal Research Centre of New Zealand. There were no cross reactivity detected with other proteins. The variant coefficient in batch and between batches varied from 3.8% to 5.6% and from 5.7% to 8.5%, respectively. All these results showed that the indirect ELISA possessed specificity, sensitivity and good reproducibility. The indirect ELISA for detection of sheep antibodies against Echinococcosis granulosa were successfully developed, which provide a fast and simple means, and can be used for clinical detection.

本研究旨在通过建立检测羊细粒棘球蚴病抗体的间接酶联免疫吸附试验（ELISA）方法，为羊细粒棘球蚴病的检测提供快速、简便的手段。作者利用DNAStar软件对GenBank上发表的细粒棘球蚴EG95蛋白的氨基酸序列进行分析，筛选出高度亲水的优势表位区EG95s，对该区域编码基因进行克隆并表达。以纯化的重组融合蛋白为包被抗原，按常规方法建立检测羊细粒棘球蚴病抗体的间接ELISA，并对各种条件进行优化。SDS-PAGE结果表明成功获得了可溶性好、表达效率高、纯化简便的重组融合蛋白GST-1EG95s和HIS-1EG95s，Western blot检测结果表明表达产物具有较好的反应原性。间接ELISA方法优化结果显示：HIS-1EG95s作为包被抗原效果优于GST-1EG95s。经统计学分析，确定间接ELISA方法的判定标准：OD450 nm值≥0.235时判定为阳性，OD450 nm值≤0.191时判定为阴性，介于二者之间则为可疑。分别对采自新疆的70份羊包虫阳性血清和70份阴性血清进行检测，结果表明该方法与新西兰Wallaceville动物研究中心提供的间接ELISA方法符合率为100%，阻断试验结果显示与其他蛋白无交叉反应，批内变异系数介于3.8%~5.6%，批间变异系数介于5.7%~8.5%，结果表明该方法特异性强、敏感性高、重复性好。作者所建立的羊细粒棘球蚴病抗体的间接ELISA检测方法有望为羊细粒棘球蚴病的检测提供快速、简便的手段。

Advances in the biology of Echinococcus and Echinococcosis, with notes on the informative achievements in China Lin Yu-guang, Lu Ming-ke, Hong Lin-xian(Parasitology Research Laboratory, Xiamen University, Xiamen 361005, China)Abstract: Echinococcosis (hydatid disease), a global serious zoonosis caused by larval stages of Echinococcus, is a medical, economic and social problem of great importance. Study ofEchinococcus and echinococcosis has progressed rapidly in the recent years. In this review, we discuss and summarize aspects of the biology, aetiology, life cycle, host-parasite relationship, distribution, and the epidemiology of infections in human and animal hosts. The informative research achievements in China are specially noted.In the world 7 Echinococcus pathogens are reported, involving 5 species in China. Among them, E. shiquicus is described as a new species from eastern Tibetan plateau in Sichuan Province by Xiao et al (2005). The Tibetan fox, Vulpes ferrilata, and plateau pika, Ochotona curzoniae, serve as the final and intermediate host respectively. In the host liver, the metacestode develops into unilocular hydatid cyst. Dog and human are free of infection so far.E.granulosus is recognized with two forms, the Northern Form(NF) and Domestic Form (DF).The typical life cycle of NF exists between wolf and large deer, and DF depends on both domestic dog and ungulates. In China, the unilocular echinococcosis pathogen belongs to DF, with heavy infection of both human and domestic animals in the northwest and northeast regions. E.multilocularis or alveolar hydatid cyst is recognized as an important zoonotic pathogen in the world, distributing throughout Europe, Siberia, Northern Japan and North America. The typical life cycle involves foxes and rodents. In China, according to the published data during 1965-2008, more than 1000 human AE（alveolar echinococcosis）cases have been recorded in 12 provinces or autonomous regions, including 70-odd counties (districts and cities). About 11 species of carnivorous animals are reported as final hosts in the world (including 5 species from China)(see Table 1). At least 9 families, 26 genera and 46 species of rodents are recorded as intermediate hosts from the world, and 8 families, 13 genera and 17 species of mammals are reported as natural intermediate hosts in China(see Table 2). After Vogel (1957) suggested E.sibiricensis as a geographic subspecies of high-latitude form, 3 subspecies, involving E. m. multilocuaris, E. m. sibiricensis and E. m. kazakhensis, are recognized by Rausch(1967). Following a series of studies on the etiology, epidemiology and metacestode development, Tang et al (1988-2007) discriminate that the 3 subspecies found from Inner Mongolia appear to have their distinct characteristics of uterus in gravid proglottid and of metacestode development in rodent hosts. Based on the excellent research works, they demonstrate that the 3 subspecies are respective species. Both E. m. multilocuaris and E. m. sibiricensis recover the original names as E. multilocuaris and E. sibiricensis, and in stead of the Russian form E. m. kazakhensis,, they describe E. russicensis sp. nov. for the memory of the late Russian parasitologist.

目的 回顾棘球绦虫及其棘球蚴病的当代研究成果，着重论述我国对本虫病原学和流行学的研究贡献。方法 评阅有关本虫病的研究资料，分析、讨论、总结病原虫种、终期和中间宿主动物，病原与宿主之间相互关系及其流行、传播规律。结论 当代全球有7种棘球绦虫，我国有5种，其中石渠棘球绦虫是青藏高原特有的新虫种。全球有20多种食肉兽类作为终期宿主，我国已知自然感染有5种，其中藏狐为宿主新记录。细粒棘球绦虫的中间宿主除大型家畜（牛、马、羊、猪）外，尚有多种鹿类有蹄动物和人体等。多房性棘球绦虫的中间宿主有9科26属46种啮齿类动物，我国已报道有6科10属14种啮齿动物为自然宿主，人体也会感染。此外绵羊、牦牛、猪等家畜虽报道有自然感染多房蚴，但病理学显示病肝组织纤维化，泡囊均无原头节，与人体感染的肝病变相似，拟是不正常的中间宿主或是多囊性的细粒棘球蚴感染。