Studies on the environmental adaptation of Echinococcus (Cyclophyllidea : Taeniidae) and its control

棘球绦虫（环叶纲：绦虫科）的环境适应及其防治研究

• 批准号: 03044016
• 负责人: KAMIYA Masao
• 金额: $ 13.44万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03044016/
• 关键词: Echinococcus; Alveolar echinoccosis; Hydatid disease; Taeniid; Perognathus; Environmental adaptability; Alternative definitive host; Coproantigen; 有鉤条虫; コレステロール; Echinococcus; Taenia; 種内変異; DNAフインガ-プリント; 猫条虫; RFLP比較; クラスタ-分析

I. ADAPTABILITY OF ECHINOCOCCUS TO ENVIRONMENTAL CHANGESa) Molecular evolution of Echinococcus : Mitochondrial DNA of Echinococcus as well as other taeniids, which were isolated from different hosts and regions, were examined for their genetic diversity by using the Bootstrap analysis. No difference in nuclotide sequence variation in the mitochondrial cytochrome C oxidase subunit 1 (CO1, containing about 350 base pairs) was observed between E. multilocularis which were isolated from naturally infected wildlife from Hokkaido as compared to those from St.Lawrence Island in Alaska. This may reflect the recent spread of E. multilocularis from Alaska to Hokkaido. However, significant difference in the CO1 nucleotide sequence was observed among E. granulosus which were isolated from different regions and the genetic diversity was so great that speciation of the cestode is thought to be in progress.b) Phylogeny of the definitive host : The evolutionary adaptability of Echinococcus can be char … More acterized by its strategy of host-switching. This is illustrated in experimental infections to produce an alternative definitive host model for E. multilocularis. Among the North American rodents, Perognathus, which belongs to the family Heteromydae, was found to be quite permissive to Echinococcus development to the tapeworm stage in the intestine. This observation is consistent with our hypothesis that rodents might be the definitive host of ancestral taeniids.c) Adaptability of Echinococcus in its intermediate host : By using Severe Combined Immunodeficient (SCID) mouse which lack functional T and B lymphocytes, it was observed that reconstitution with splenocytes and thymocytes invest resistance against E. multilocularia secondary infection in these animals. However, reconstitution with B cells resulted in better development of the cyst. Thus the immune system may work either way in E. multilocularis infection in its intermediate host.II. CONTROL OF ECHINOCOCCUSa) E. granulosus control program in Uruguay : The prevalence of cystic hydatid disease, which is caused by E. granulosus, in Uruguay is thought to be as high as 3% in the human population. Of the 639 sheep examined, 42% were found to be infected with hydatid cysts. However, only 5% of these infected sheep had fertile cysts which contain protoscoleces. In rural areas, sheep are slaughtered everyday by the farmers themselves and the chances of dogs having access to the infected offal is very great. This actually helps to perpetuate the life cycle of E. granulosus in Uruguay. Analysis of the age of the infected sheep shows that the infection rate proportionately increase with age, with protoscoleces-containing cysts being found only in sheep of 3 years of age and above. In addition to the continuation of the deworming of dogs, the importance of sheep in the maintenance of life cycle of E. granulosus should be also considered in the control program.b) Simplification of diagnosis in dogs : A sensitive method based on ELISA was developed for the detection of coproantigen in Echinococcus-infected dog feces. The diagnosis can be performed safely without health hazard to human. Characterization of coproantigen is presently in progress. Moreover, the mechanism of immune expulsion of the worm is also under investigation with the final objective of developing a vaccine for dogs. This line of thought is being followed up with the establishment of an oversea cooperation project sponsored by Japan International Cooperation Agency(JICA) in Uruguay. Less

I.棘球绦虫对环境变化的适应性a）棘球绦虫的分子进化：利用Bootstrap分析方法，对棘球绦虫和其他绦虫的线粒体DNA进行了遗传多样性分析。线粒体细胞色素C氧化酶亚基1（CO1，含约350个碱基对）核苷酸序列变异在E.多室的，其中分离自自然感染的野生动物从北海道相比，那些从圣劳伦斯岛在阿拉斯加。这可能反映了E.产于阿拉斯加到北海道的多室珊瑚。而CO1核苷酸序列在E. B）终末宿主的系统发育：棘球绦虫的进化适应性可以通过对棘球绦虫的形态学特征的分析来判断，棘球绦虫的进化适应性可以通过对棘球绦虫的形态学特征的分析来判断 ...更多信息 其特点是主机切换策略。这在实验感染中得到了说明，以产生E.多房的在北美啮齿类动物中，发现属于异菌科的Perognathus非常允许棘球绦虫在肠道中发育到绦虫阶段。c）棘球绦虫在中间宿主中的适应性：通过使用缺乏功能性T和B淋巴细胞的严重联合免疫缺陷（SCID）小鼠，观察到用脾细胞和胸腺细胞重建后对E.在这些动物中的多房虫继发感染。然而，用B细胞重建导致囊肿更好地发育。因此，免疫系统在E.在其中间宿主的多房感染。棘球绦虫的防治乌拉圭细粒棘球蚴病控制计划：由E.在乌拉圭，细粒棘球绦虫被认为在人类人口中高达3%。在639只绵羊中，42%被发现感染了包虫囊肿。然而，只有5%的这些感染的羊有肥沃的囊肿，其中包含原绦虫。在乡郊地区，羊只每天都由农民自行屠宰，狗只接触受感染内脏的机会非常大。这实际上有助于延续E的生命周期。granulosus在乌拉圭。对感染羊的年龄分析表明，感染率随年龄的增长而成比例增加，仅在3岁及以上的羊中发现含原孢子囊。除继续对犬进行驱虫外，绵羊在维持E。B）简化犬的诊断：建立了一种灵敏的ELISA检测犬棘球蚴粪抗原的方法。该诊断可以安全地进行，不会对人体健康造成危害。粪抗原的鉴定目前正在进行中。此外，蠕虫的免疫驱逐机制也在研究中，最终目标是开发犬用疫苗。根据这一思路，日本国际协力事业团在乌拉圭发起了一个海外合作项目。少

项目成果

Playford,M.C.: "Immune response to Echinococcus multilocularis infection in the mouse model;a review." Japanese Journal of Veterinary research. 40. 113-130 (1992)

Playford, M.C.：“小鼠模型中对多房棘球绦虫感染的免疫反应；综述。”

Sato, H., Kamiya, H., Tenora, F. & Kamiya, M: "Anoplocephaloides dentatoides sp. n. from the gray red-backed vole, Clethrionomys rufocanus bedfordiae, in Hokkaido, Japan." J. Helminthol. Soc. Wash.60. 105-110 (1993)

佐藤 H.、神谷 H.、特诺拉 F.

Alkarmi,T.,Dar,F.K.& Ooi,H.K.: "Echinococcus multilocularis:Effect of size of inoculum and route of infection on metastasis,amyloidogenesis and alveolar hydatid cyst mass in mice." J.Vet.Med.Sci.56(in press). (1994)

阿尔卡米，T.，达尔，F.K.

Iwaki, T., Tenora, F., Oku, Y. & Kamiya, M.: "Andrya apodemi n. sp. (Cestoda, Anoplocephalidae), a parasite of Apodemus argenteus (Rodentia, Muridae) from Hokkaido Japan." J. Helminthol. Soc. Wash.61. in press (1994)

岩城 T.、特诺拉 F.、奥库 Y.

Sato,H.: "Anoplocephaloides dentatoidessp.n.from the Gray Red-backed Vole,Clethrionomys rufocanus bedfordiae,in Hokkaido,Japan." Journal of Helminthological Society of Washington,. 60. (1993)

Sato, H.：“Anolocephaloides dentatoidessp.n.，来自日本北海道的灰红背田鼠，Clethrionomys rufocanus bedfordiae。”