Development of diagnostic systems, reference collections and molecular epidemiology studies for important arboviral pathogens of livestock in India

该项目“印度家畜重要虫媒病毒病原体的诊断系统、参考资料收集和分子流行病学研究的发展”将建立在皮尔布赖特研究所、格拉斯哥大学、约翰·英尼斯研究所和(英国)皇家兽医学院的同事与印度希萨尔兽医和动物科学大学的同事之间建立的联系，并与印度南部从事虫媒病毒工作的同事建立联系。虫媒病毒疾病的暴发是印度畜牧业/农业社区的重大负担。血清学数据显示，26种蓝舌病毒(BTV)血清型中有21种存在于印度，是世界上BTV多样性水平最高的国家之一。近几十年来，印度绵羊Bt疫情的严重程度大幅上升，在一些地区达到30%，可能是由于引入了外来菌株。然而，很少有印度BTV分离株具有基因或表型特征，这给当地诊断验证和控制策略(包括疫苗的开发)造成了重大障碍。在过去的25年里，欧洲出现了多种BTV和其他虫媒病毒株，可能与气候和全球贸易的变化有关。然而，缺乏有关全球毒株多样性和分布的数据，限制了我们理解、应对和控制这些事件的能力。BTV全球数据库的不完整性质限制了我们确定Bt暴发菌株地理来源的能力。印度的许多地方性虫媒病毒也存在类似的问题(Myers等人1971年；Padbitri等人2002年)。我们将通过分离、鉴定和描述来自印度的虫媒病毒来解决这些知识空白，以研究它们的分布、丰度、关系和导致疾病暴发的运动。该项目的主要重点是BTV，尽管用于检测和分离病毒的诊断样本也将提供该地区其他虫媒病毒的材料和可能的分离株。皮尔布赖特的参考资料收集提供了不同的环状病毒和序列数据，用于诊断分析的开发和评估(通过RT-PCR)。这些检测确定了自1998年以来入侵欧洲的BTV类型，已成为世界各地广泛接受的BTV诊断、监测和分型的“一线”工具。然而，它们尚未在印度得到广泛验证或部署。来自皮尔布赖特收集的BTV分离株也被用于开发/评估成功根除英国和北欧BTV 8型的灭活疫苗株。将在印度产生具有良好特征和文件记载的病毒分离株，作为“印度虫媒病毒”参考集合的基础，特别侧重于BTV和其他环状病毒。这将为当地开发相关疫苗(种子库和挑战毒株)以及验证/进一步开发用于在印度次大陆识别、检测和监测这些病毒的诊断分析提供材料。将“印度参考收藏”与皮尔布赖特的现有收藏联系起来，将增加全球资源和我们对这些病毒的了解。诊断、分离、测序、系统发育和病毒存储将在皮尔布赖特的协助下在印度进行。系统发育和进化分析将在皮尔布赖特和格拉斯哥进行。病理学研究将在皮尔布赖特、RVC和印度进行。该项目将利用John Innes(JIC)(P3)在植物表达技术方面的最新发展，为BTV血清分型生产低成本试剂。这将在英国和印度的植物和动物科学之间建立联系。将在日本联合免疫中心和皮尔布赖特开发下一代血清学分析，以便在皮尔布赖特和印度进行评估。

This project "Development of diagnostic systems, reference collections and molecular epidemiology studies for important arboviral pathogens of livestock in India" will build on established links between colleagues at The Pirbright Institute, the University of Glasgow, The John Innes Institute and the Royal Veterinary College (in the UK) with The University of Veterinary and Animal Sciences at Hisar in India, creating links with colleagues working with arboviruses in southern India. Outbreaks of arboviral diseases are a significant burden on livestock / farming communites in India. Serological data show that 21 of the 26 bluetongue virus (BTV) seroptypes exist in India, one of the highest levels of BTV diversity anywhere in the world. The severity of BT outbreaks in Indian sheep has increased significantly in recent decades, reaching 30% in some areas, possibly due to introduction of exotic strains. However, very few Indian BTV isolates have been genetically or phenotypically characterised, creating a major barrier to local validation of diagnostics and to control strategies, including development of vaccines. During the past 25 years, multiple strains of BTV and other arboviruses have emerged in Europe, possibly linked to changes in climate and global trade. However, a lack of data concerning global strain-diversity and distribution limits our ability to understand, respond to and control these events. The incomplete nature of the global database for BTV limits our ability to Identify the geographic origin of BT outbreak-strains. Similar problems exist for many endemic arboviruses in India (Myers et al 1971; Padbidri et al 2002). We will address these knowledge-gaps by isolating, identifying and characterising arboviruses from India, to study their distribution, abundance, relationships, and movements that result in disease outbreaks. The primary focus of the project is BTV, although diagnostic samples used to detect and isolate viruses, will also provide materials and potentially isolates of other arboviruses from the region. The reference collection at Pirbright provides different orbiviruses and sequence data, for development and evaluation of diagnostic assays (by RT-PCR). These assays, which identified the BTV types that invaded Europe since 1998, have become widely accepted 'front-line' tools for diagnosis, surveillance and typing of BTV around the world. However they have not yet been widely validated or deployed in India. BTV Isolates from the Pirbright collection were also used to develop / evaluate inactivated vaccine strains that successfully eradicated BTV type 8 from the UK and northern Europe . Well characterised and documented virus isolates will be generated in India, as a basis for a reference collection of 'Indian arboviruses', focussing particularly on BTV and the other orbiviruses. This will provide materials for local development of relevant vaccines (seed stocks and challenge strains) and validation / further-development of diagnostic assays for identification, detection and surveillance of these viruses on the Indian subbcontinent. Linking 'Indian-reference-collections', to the existing collection at Pirbright, will add to the global resources and our knowledge concerning these viruses. Diagnosis, isolations, sequencing, phylogenetics and virus storage will be undertaken in India, with assistance from Pirbright. Phylogenetic and evolutionary analyses will be performed at Pirbright and Glasgow. Pathology studies will be carried out at Pirbright, at the RVC and in India. The project will take advantage of recent developments in plant-based expression technologies at John Innes (JIC) (P3), to generate low-cost reagents for BTV serotyping. This will create links between plant and animal science in the UK and in India. Development of next generation serological assays will take place at JIC and Pirbright, for evaluation at Pirbright and in India.