Genetic and genomic approaches to study the disease ecology of Trichomonas gallinae

禽滴虫病是由单细胞寄生虫鸡毛滴虫引起的，是一种有充分记录的鸽子、鸽子和猛禽的地方病，偶尔在广泛的地理区域发生。鸡锥虫被认为是鸽子和鸽子上消化道（口腔和嗉囊）的正常居民，在压力大的时期（包括饲养幼鸽）可能导致疾病。滴虫病会导致因消瘦和脱水而缓慢死亡，因为口腔和作物上的大病变会阻止受感染的鸟类吞咽。在鸽子和鸽子中，鸡绦虫在求偶和育雏期间通过食物反刍后的唾液传播，而猛禽在捕食受感染的鸟类宿主时也会被感染。2005年，雀毛滴虫病首次在英国的雀群中被发现，随后蔓延到欧洲，造成流行病死亡和大量种群下降。2007年，加拿大沿海地区出现了雀毛滴虫病，造成了类似的发病率和死亡率事件，特别是在紫翅雀和美洲金翅雀种群中。***我们之前的研究表明，英国流行菌株存在于加拿大大西洋，但存在更大的遗传变异；提示该地区的雀滴虫病可能不是由单一溢出事件引起的。重要的是，我们通过分析从后院鸟类饲养点收集的鸟类种子样本，发现寄生虫可以在潮湿的种子中持续存在，并且通过对照实验室研究，寄生虫可以在潮湿的种子中复制并保持活力长达48小时。这表明，最近全年鸟类喂养和浇水的趋势（与筑巢期一致；6 - 7月）可能与雀滴虫病的出现和维持有关。******在目前的提案中，我们计划通过解决四个目标来探讨关于这种疾病的出现和维持的悬而未决的问题：******1. 1。目的：探讨加拿大鸡尾绦虫（T. gallinae）的遗传多样性及其潜在来源。2 .探讨城市鸟类饲养点与农村自然饲养点间鸡尾绦虫流行、传播及死亡率的空间差异。[3]探讨气候对鸡瘿菌持续繁殖的影响。表征城乡环境中宿主-寄生虫相互作用的基本分子机制。******总体目标是提供关于加拿大雀毛滴虫病流行病学的科学证据，以指导联邦、省和地区野生动物机构和负责预测流行病未来轨迹和/或采取行动预防或减轻该疾病对受影响物种的重大影响的管理人员的政策和决定

Avian trichomonosis, caused by the single-celled parasite Trichomonas gallinae, is a well-documented endemic disease of pigeons, doves and birds of prey that occurs occasionally over a widespread geographic area. T. gallinae is considered a normal inhabitant of the upper digestive tract (mouth and crop) of pigeons and doves that may contribute to disease during stressful periods including rearing young. Trichomonosis causes slow death from emaciation and dehydration because large lesions in the mouth and crop prevent affected birds from swallowing. In pigeons and doves, T. gallinae is transmitted via saliva following regurgitation of food during courtship and rearing young, while birds of prey are exposed when they prey upon infected avian hosts. Finch trichomonosis was first recognized in finch populations in the UK in 2005 which subsequently spread to Europe causing epidemic mortalities and extensive population declines. In 2007, finch trichomonosis emerged in the Canadian Maritimes, causing similar morbidity and mortality events particularly in purple finch and American goldfinch populations.***Our previous research has shown that the UK epidemic strain is present in Atlantic Canada but that greater genetic variation is present; suggesting that finch trichomonosis in this region may not have arisen by a single spillover event. Importantly, we have shown through analysis of bird seed samples collected from a backyard bird feeding site experiencing mortalities that the parasite can persist in moist seed and through controlled laboratory studies that the parasite can replicate and remain viable in moist seed for up to 48 hrs. This indicates that the recent trend towards year round bird feeding and watering (coinciding with nesting periods; June-July) could be associated with the emergence and maintenance of finch trichomonosis.******In the current proposal we plan to explore outstanding questions on the emergence and maintenance of this disease by addressing four objectives.******1. To explore the genetic diversity and potential origin of T. gallinae in Canada.***2. To investigate spatial differences in prevalence, transmission and mortality due to T. gallinae between urban bird feeding sites and rural natural feeding sites.***3. To investigate the role of climate in the persistence of T. gallinae.***4. To characterize fundamental molecular mechanisms in host-parasite interactions between urban and rural environments. ******The overall aim is to provide science-based evidence on the epidemiology of Canadian finch trichomonosis that will guide policy and decisions of Federal, Provincial and Territorial wildlife agencies and managers responsible to predict the future trajectory of epidemics and/or act to prevent or mitigate the significant impacts of this disease on affected species.**