Population genetics of parasitic nematodes of livestock; the spread of anthelmentic resistance and range expansion in Haemonchus spp

家畜寄生线虫的群体遗传学；

• 批准号: 371529-2009
• 负责人: Gilleard, John
• 金额: $ 1.75万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=483607
• 关键词: Population; genetics; parasitic; nematodes; livestock

Parasitic roundworms (nematodes) are important agents of disease in both humans and animals. Such infections are ubiquitous in livestock (cattle, sheep and goats) worldwide and are amongst the most economically important diseases to agriculture. It has been estimated they cost the North American cattle industry more than $2 billion per year. Roundworm control is dependent upon the routine treatment of livestock with drugs (anthelmintics) but many roundworm parasites are now resistant to these drugs making control increasingly difficult.This project focuses on a group of livestock parasites called Haemonchus.There are a number of different species of Haemonchus that live in the stomach of livestock feeding on blood and causing anaemia. These parasites originated in Africa but have spread around the world with livestock movement and, although originally adapted to the tropics, they are now spreading to more northern latitudes including Canada, Western Europe and Scandanavia. This project will develop DNA based tests to detect and identify these parasites. These tools will be used to determine which Haemonchus species are most important in cattle, sheep, goats and wildlife in different regions of the world and in different situations.As well as studying these parasites in tropical regions, we will investigate the spread of the parasite through livestock and wildlife in Canada.We will also use DNA-based techniques to detect drug resistant parasites by detecting mutations in the parasite's DNA that confer resistance to an important class of drugs. We will study how these resistance-conferring mutations are spread between parasite populations. One particular concern is the risk that these mutations could spread from one parasite species to another. This is a particular worry in livestock because drug resistance is extremely common in sheep and goat parasites but is only now emerging in cattle parasites. Consequently we will investigate whether there is spread of drug resistance between sheep and cattle parasites. This project will provide important information needed to control the development of drug resistance and prevent the movement of parasites into new regions and wildlife populations.

寄生性蛔虫（线虫）是人类和动物疾病的重要病原体。这种感染在全世界的牲畜（牛、绵羊和山羊）中普遍存在，并且是对农业最经济重要的疾病之一。据估计，北美养牛业每年损失超过20亿美元。蛔虫的控制依赖于对牲畜进行常规药物治疗（驱虫剂），但许多蛔虫寄生虫现在对这些药物产生抗药性，使控制越来越困难。本项目重点关注一组称为血矛线虫的牲畜寄生虫。有许多不同种类的血矛线虫生活在牲畜的胃中，以血液为食，并导致贫血。这些寄生虫起源于非洲，但随着牲畜的移动而传播到世界各地，虽然最初适应热带地区，但现在正在传播到更北方纬度，包括加拿大，西欧和斯堪的纳维亚。该项目将开发基于DNA的测试来检测和识别这些寄生虫。这些工具将用于确定在世界不同地区和不同情况下，哪些血矛线虫物种在牛、绵羊、山羊和野生动物中最重要。我们将调查寄生虫通过加拿大牲畜和野生动物的传播。我们还将使用DNA-通过检测寄生虫DNA中的突变来检测抗药性寄生虫，这些突变赋予了对一类重要药物的抗药性。我们将研究这些赋予抗性的突变如何在寄生虫种群之间传播。一个特别令人担忧的问题是，这些突变可能会从一种寄生虫传播到另一种寄生虫。这在家畜中是一个特别令人担忧的问题，因为抗药性在绵羊和山羊寄生虫中非常普遍，但现在才出现在牛寄生虫中。因此，我们将调查绵羊和牛寄生虫之间是否存在耐药性传播。该项目将提供控制耐药性发展和防止寄生虫进入新地区和野生动物种群所需的重要信息。