Wachira T M, Bowles J, Zeyhle E, McManus D P
Molecular Helminthology Laboratory, Queensland Institute of Medical Research, Brisbane, Australia.
Am J Trop Med Hyg. 1993 Apr;48(4):473-9. doi: 10.4269/ajtmh.1993.48.473.
Previous studies have shown that camel and sheep strains of the cystic hydatid parasite Echinococcus granulosus occur in Kenya. We examined 208 larval isolates and 40 worm samples of E. granulosus from various hosts in Kenya using restriction fragment length polymorphism analysis of a segment of ribosomal DNA amplified by the polymerase chain reaction. This was in an effort to determine whether additional strains of E. granulosus occur in Kenya, to examine the level of genetic heterogeneity within the sheep/dog and camel/dog strains previously identified, and to map out their intermediate host range and geographic distribution in Kenya. We confirmed the existence of the two strains in Kenya and showed that the distribution of the camel strain appears restricted to the Turkana region, where camels are kept as livestock. The intermediate host range for both strains seems to be similar except that humans appear refractory to infection with the camel strain. We have also shown that although the life-cycle patterns of the two strains overlap both geographically and in intermediate and definitive hosts, the strains maintain their homogeneous genetic identity.
先前的研究表明,肯尼亚存在细粒棘球绦虫这种囊性包虫寄生虫的骆驼和绵羊毒株。我们使用聚合酶链反应扩增的核糖体DNA片段进行限制性片段长度多态性分析,检测了来自肯尼亚不同宿主的208份细粒棘球绦虫幼虫分离株和40份虫体样本。目的是确定肯尼亚是否存在其他细粒棘球绦虫毒株,检查先前鉴定出的绵羊/犬和骆驼/犬毒株内的遗传异质性水平,并明确它们在肯尼亚的中间宿主范围和地理分布。我们证实了肯尼亚存在这两种毒株,并表明骆驼毒株的分布似乎局限于图尔卡纳地区,该地区将骆驼作为家畜饲养。两种毒株的中间宿主范围似乎相似,只是人类似乎对骆驼毒株的感染具有抗性。我们还表明,尽管两种毒株的生命周期模式在地理上以及中间宿主和终末宿主方面存在重叠,但这些毒株保持了它们的同源遗传特性。