Abstract:
Exsheathment is crucial in the transition from free-living to parasitic phase for most strongyle nematode species. A greater understanding of this process could help in developing new parasitic control methods. This study aimed to identify commonalities in response to exsheathment triggers (heat acclimation, CO2 and pH) in a wide range of species (Haemonchus contortus, Trichostrongylus spp., Cooperia spp., Oesophagostomum spp., Chabertia ovina, and members of the subfamily Ostertagiinae) from sheep, cattle and farmed deer. The initial expectation of similarity in pH requirements amongst species residing within the same organ was not supported, with unexpected pH preferences for exsheathment of Trichostrongylus axei, Trichostrongylus vitrinus, Trichostrongylus colubriformis and Cooperia oncophora. We also found differences between species in their response to temperature acclimation, with higher exsheathment in response to heat shock observed for H. contortus, Ostertagia ostertagi, T. axei, T. vitrinus and Oesophagostomum sikae. Furthermore, some species showed poor exsheathment under all experimental conditions, such as Cooperia curticei and the large intestinal nematodes C. ovina and Oesophagostomum venulosum. Interestingly, there were some significant differences in response depending on the host from which the parasites were derived. The host species significantly impacted on the exsheathment response for H. contortus, Teladorsagia circumcincta, T. vitrinus and T. colubriformis. Overall, the data showed variability between nematode species in their response to these in vitro exsheathment triggers, highlighting the complexity of finding a common set of conditions for all species in order to develop a control method based on triggering the exsheathment process prematurely.
摘要:
对于大多数强线虫物种而言,出鞘对于从自由生活到寄生阶段的过渡至关重要。对这一过程的更多了解可以帮助开发新的寄生控制方法。本研究旨在确定响应外鞘触发因素的共性(热适应,CO2和pH值)在多种物种中(扭曲的Haemonchus,毛线菌属。,Cooperiaspp.,食管造口菌属。,Chabertiaovina,和Ostertagiinae亚科的成员)来自绵羊,牛和养殖鹿。最初对同一器官内物种之间的pH要求相似的期望没有得到支持,具有意想不到的pH偏好,玻璃化毛线体,胶毛刚毛和孔雀鱼。我们还发现物种之间对温度适应的反应存在差异,对于H.contortus观察到的对热休克的响应较高的出鞘,Ostertagiaostertagi,T.Axei,T.玻璃化和食管鼻孔。此外,一些物种在所有实验条件下都表现出不良的出鞘,如Cooperiacurticei和大肠线虫。有趣的是,根据寄生虫来源的宿主,反应存在一些显着差异。寄主物种对H.contortus的出鞘反应有显著影响,Teladorsagiacircincta,T.玻璃化和T.colubriformis。总的来说,数据显示,线虫物种对这些体外出鞘触发因素的反应存在差异,强调为所有物种找到一组共同条件的复杂性,以便开发一种基于过早触发出鞘过程的控制方法。