Combining molecular biology and computer modelling to enhance control of liver fluke in livestock across agricultural landscapes

结合分子生物学和计算机建模，加强对农业领域牲畜肝吸虫的控制

• 批准号: 2750173
• 金额: --
• 依托单位: Aberystwyth University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2750173
• 关键词: Combining; molecular; biology; computer; modelling

Liver fluke (Fasciola hepatica) is a highly pathogenic trematode parasite that is highly prevalent in cattle and sheep globally, with its disease, fasciolosis estimated to cost European livestock producers over £2 billion annually. Climate change and anthelmintic resistance are driving increasing liver fluke prevalence globally. This increase in prevalence is seriously impacting animal health, welfare and productivity, and threatening the sustainability of livestock production in certain regions.To alleviate this threat, and to sustainably manage liver fluke in future decades, alternative non-chemical control strategies are required. These alternative strategies may target the F. hepatica lifecycle, which revolves around an intermediate snail host (Galba truncatula). This snail is only present in areas on pastureland where optimal environmental and microclimatic conditions allow it to thrive. Strategies including grazing rotation, temporary or permanent fencing of risk areas and targeted treatment of livestock to reduce pasture contamination of F. hepatica eggs can impede the lifecycle. However, major barriers prevent the mass adoption of these alternative control strategies. Poor understanding of the spatial distribution G. truncatula habitats on farms impedes on the ability of farmers to successfully apply measures targeting the snail. There is also limited information regarding how these alternative strategies can be optimally applied, including which periods of the year they should be employed and for how long.In recent years, the project's supervisory team have developed novel research tools that allow researchers to investigate the epidemiology of G. truncatula and F. hepatica at field level. These include the development of environmental DNA assays which can identify the presence of G. truncatula on farmland (Jones et al., 2018), and mechanistic modelling techniques which can accurately model F. hepatica infection risk over time at farm level (Beltrame et al., 2018). This project aims to utilise these tools to develop and evaluate farm specific guidance for successful application of non-chemical control methods for F. hepatica control on UK farms.During the PhD programme, the prospective student will evaluate and compare a range of DNA extraction methods and molecular tools to identify optimal methodology for G. truncatula eDNA capture, extraction and amplification. The optimal methodologies identified will then be applied to survey G. truncatula habitats on multiple UK farms. Environmental and climatic measurements will also be gathered in these sampling sites and analysed in conjunction with eDNA survey results to identify factors associated with the presence of G. truncatula snails in water-saturated habitats on farmland. Finally, mechanistic models will evaluate the impact of grazing rotations, temporary and permanent fencing of G. truncatula habitats and targeted treatment to minimise pasture contamination of fluke eggs on future F. hepatica infection risk in grazing livestock on farms studied and mapped via eDNA survey. These models will also evaluate the optimal timeframe for the application of these strategies, how weather interacts with farm topography and structure to affect their success, and how pasture architecture can be altered to enhance impact of grazing-based control, for fluke and co-infecting nematode parasites.The prospective student will acquire inter-disciplinary skills in molecular biology, parasitology, computational modelling and generic research methods and communication. Specifically, the prospective student will develop skills to perform a range of DNA extraction and amplification methodologies, to morphologically identify intermediate snail host and parasite life stages and to develop and apply mechanistic models. Training will be provided by the supervisory team and by Aberystwyth University's Graduate School Doctoral Training Programme.

肝片吸虫（Fasciola hepatica）是一种高致病性吸虫寄生虫，在全球范围内的牛和羊中高度流行，其疾病肝片吸虫病估计每年使欧洲畜牧业生产者损失超过20亿英镑。气候变化和驱虫剂耐药性正在推动全球肝吸虫患病率上升。这种流行率的增加严重影响动物健康、福利和生产力，并威胁到某些地区畜牧业生产的可持续性。为了减轻这种威胁，并在未来几十年可持续地管理肝吸虫，需要替代的非化学控制策略。这些替代策略可以针对F。肝的生命周期，围绕中间蜗牛主机（Galba truncatula）。这种蜗牛只存在于最佳环境和小气候条件允许它茁壮成长的牧场地区。采取轮牧、临时或永久性围封风险区和有针对性地治疗牲畜等策略，以减少牧草对F。肝虫卵会阻碍生命周期然而，主要的障碍阻止了这些替代控制策略的大规模采用。对空间分布的认识不足G。农场中的蒺藜生境阻碍了农民成功采取针对蜗牛的措施的能力。关于如何最佳地应用这些替代策略的信息也很有限，包括一年中的哪些时间段应该使用它们以及使用多长时间。近年来，该项目的监督团队开发了新的研究工具，使研究人员能够调查G. truncatula和F.在田间水平的肝。这些包括发展环境DNA检测，可以识别G。农田上的蒺藜（Jones等人，2018），和机械建模技术，可以准确地模拟F。在农场水平上随着时间推移的肝感染风险（Beltrame等人，2018年）。该项目旨在利用这些工具来开发和评估农场特定的指导，以成功应用非化学控制方法。在博士课程期间，未来的学生将评估和比较一系列DNA提取方法和分子工具，以确定G.蒺藜eDNA的捕获、提取和扩增。然后将确定的最佳方法应用于调查G。英国多个农场的蒺藜栖息地。环境和气候测量也将在这些采样点收集，并结合eDNA调查结果进行分析，以确定与G的存在有关的因素。在农田的水饱和的栖息地的蒺藜蜗牛。最后，机制模型将评估放牧轮作，临时和永久围栏的影响G。蒺藜栖息地和有针对性的治疗，以尽量减少牧草污染的吸虫卵对未来F。通过eDNA调查研究和绘制了农场放牧牲畜的肝感染风险。这些模型还将评估应用这些策略的最佳时间框架，天气如何与农场地形和结构相互作用以影响其成功，以及如何改变牧场结构以增强基于放牧的控制的影响，对于吸虫和共感染线虫寄生虫。未来的学生将获得分子生物学，寄生虫学，计算建模和通用研究方法和通信。具体来说，未来的学生将发展技能，执行一系列的DNA提取和扩增方法，形态学识别中间蜗牛宿主和寄生虫的生命阶段，并开发和应用机械模型。培训将由监督小组和阿伯里斯特威斯大学研究生院博士培训方案提供。