Martini Matilde, Dumendiak Sonja, Gagliardo Anna, Ragazzini Francesco, La Rosa Letizia, Giunchi Dimitri, Thielen Frank, Romig Thomas, Massolo Alessandro, Wassermann Marion
Ethology Unit, Department of Biology, University of Pisa, 56126 Pisa, Italy.
Parasitology Unit 190p, Institute of Biology, University of Hohenheim, 70599 Stuttgart, Germany.
Pathogens. 2022 Nov 24;11(12):1414. doi: 10.3390/pathogens11121414.
Muskrats (Ondatra zibethicus) are competent intermediate hosts for Echinococcus multilocularis, are frequently infected with this zoonotic cestode, and have even been proposed as a target species to monitor endemicity levels of this parasite. However, their contribution to maintaining the parasitic lifecycle is still unclear. To obtain data on infection frequency and reproductive potential, 280 muskrats from the Grand Duchy of Luxembourg were examined for cestode larvae in the years 2013−2017. Based on morphological and molecular identification, Echinococcus multilocularis was found at a prevalence of 14.6%. Other metacestodes were Hydatigera kamiyai, with a prevalence of 45.7%, Taenia martis with 8.9%, Taenia polyacantha with 5.0%, and Versteria mustelae, which was found in 0.7% of all muskrats. More than 80% of E. multilocularis-infected muskrats contained fertile metacestodes with a mean number of >300,000 (and up to 1,609,816) protoscoleces, which is by far the highest reproductive potential known from any intermediate host species in Europe. Temporal analysis of E. multilocularis prevalence within the study period (and in comparison with earlier data) strongly indicates a robust increase in the studied area. Host age seemed to be an important risk factor for infection, as well as co-infections with Hydatigera kamiyai. A preference for the right medial lobe of the liver as the location of E. multilocularis metacestode was observed. Intraspecific genetic variation among 89 discrete E. multilocularis metacestodes was non-existent based on 300−1590 bp sections of cox1. This is a stark contrast to H. kamiyai, of which nine haplotypes were found on a short 318 bp section of cox1, resulting in genetic diversity in the small country of Luxembourg at a similar level than previously reported from large stretches of Europe and northern Asia.
麝鼠（麝鼠属）是多房棘球绦虫的适宜中间宿主，经常感染这种人畜共患绦虫，甚至有人提议将其作为监测该寄生虫地方流行程度的目标物种。然而，它们在维持寄生虫生命周期中的作用仍不清楚。为了获取感染频率和繁殖潜力的数据，2013 - 2017年对来自卢森堡大公国的280只麝鼠进行了绦虫幼虫检查。基于形态学和分子鉴定，发现多房棘球绦虫的感染率为14.6%。其他绦虫蚴有卡氏多头绦虫，感染率为45.7%，马氏绦虫为8.9%，多棘绦虫为5.0%，以及鼬型韦氏绦虫，在所有麝鼠中的发现率为0.7%。超过80%感染多房棘球绦虫的麝鼠含有可育的绦虫蚴，平均原头节数量>300,000个（最多可达1,609,816个），这是欧洲任何中间宿主物种中已知的最高繁殖潜力。对研究期间多房棘球绦虫感染率的时间分析（并与早期数据比较）强烈表明研究区域内感染率显著上升。宿主年龄似乎是感染的一个重要风险因素，同时也是与卡氏多头绦虫共感染的风险因素。观察到多房棘球绦虫蚴在肝脏右中叶的定位偏好。基于细胞色素氧化酶亚基1（cox1）的300 - 1590 bp片段，89个离散的多房棘球绦虫蚴之间不存在种内遗传变异。这与卡氏多头绦虫形成鲜明对比，在cox1的短318 bp片段上发现了卡氏多头绦虫的9种单倍型，导致卢森堡这个小国的遗传多样性水平与此前在欧洲大片地区和亚洲北部报道的相似。
