甲型流感病毒与淡水环境中其他微生物相互作用关系的研究

Influenza A has caused serious public health problems. Intervention from the host animals is the main cause for the maintenance and epidemic of this disease, and also is the platform of reassortment and mutation for the pathogens, i.e., influenza A viruses, by which to form a new subtype of virus. However, series of the problems such as where and how the influenza viruses existed in when they didn’t contaminate vertebrates, and which biotypes could be infected by influenza A viruses other than vertebrates, so did their mechanisms, still remained unknown. As the “natural gene pools” of influenza A virus, the waterfowls have their life history closely related to the water environment. So, the influenza A virus carried by them inevitably have close relationships with the water environment microorganism..Hongze Lake and Changjiang Estuary of Chongming Island are two important habitats for migratory birds in winter, moreover, in these two areas, there were assorted subtypes influenza A viruses isolated frequently. In this study, we collect freshwater samples from the two areas in different seasons, especially, the winter, for reason of the influenza’s high prevalence rate in this season. Stage-centrifugation was used for enriching freshwater microorganisms, and then RNA-Seq and Illumina Miseq were carried out for sequencing the total transcription of RNA. By these ways, the structure and abundance of microbial populations in aquatic environment were obtained, which also including the genomes of influenza A viruses if there exist. According to the abundance of microbial populations ranking, several pure cultures will be established. Co-cultures between freshwater-borne microorganisms and influenza A viruses will be done later, and then, research on the functions and their mechanisms of these freshwater-borne microorganisms maintaining or proliferating influenza A virus will be launched on the levels of molecular and cell biology..This study not only has some practical significance to the storage and spread of influenza virus, the epidemic warning of the epidemic situation, and the development and production of the vaccine, and also has some theoretical value on the relationship between virus and microorganism.

甲型流感可引起严重的公共卫生问题，动物的介入是甲型流感得以维持和流行的主因，又是流感病毒通过基因变异与重排形成新亚型病毒的平台。但在甲流流行的静息期，病毒以何种形式存在于何处，与环境微生物相互作用的关系和机制如何尚不清楚。作为该病毒“天然基因库”的水禽，其生活史与水环境息息相关，所携病毒不可避免地与水环境微生物发生密切联系。.洪泽湖及崇明岛长江口是候鸟在华东越冬的重要栖息地，在两地均有多次分离到不同亚型甲型（禽）流感病毒的记录。本研究通过RNA-Seq测序，对这两个水域中淡水环境微生物的种群结构与丰富度进行分析，建立特异性检出甲流病毒基因片段的样品所对应的高丰度微生物纯培养，并与病毒共培养。旨在揭示淡水环境微生物在甲流病毒维持与增殖环节中的作用及可能机制，不但对流感病毒的储存传播、疫情的流行预警以及疫苗的研制生产有着一定的实践意义，且对阐述病毒与微生物相互作用的关系也具有一定的理论价值。

动物的介入是甲型流感得以维持和流行的主因，又是流感病毒通过基因变异与重配形成新亚型的平台。作为病毒“天然基因库”的水禽，其生活史与水环境息息相关，所携病毒不可避免地与水环境微生物发生密切联系。本研究采集候鸟的重要越冬栖息地洪泽湖的环境水体样本，通过RNA-Seq测序，对其中的淡水环境微生物的种群结构与丰富度进行分析，探讨环境微生物与甲型流感病毒之间可能存在的共生关系，建立特定微生物的纯培养并与甲型流感病毒共培养，旨在揭示淡水环境微生物在甲型流感病毒维持与增殖环节中的作用及可能的机制。本研究在门、属、种三个分类阶元上探讨了洪泽湖区高丰度水体微生物的类别，并专门探讨了其中的病毒类别。.研究提出作为通过基因重配形成甲型流感病毒新亚型的“混合器”性质宿主应为半水生哺乳动物（semiaquatic mammals），特别是水貂（Neovison vison），而非传统观点所认为的猪。该研究赋予水体及水环境微生物在甲型流感病毒流通与传播过程中独特的意义，提出甲型流感病毒通过基因重配形成新亚型可能涉及两个位于不同生境之下的循环，即水生栖息地循环与陆生栖息地循环。在水生栖息地循环中，甲型的禽流感病毒时刻处在传播，变异和适应水生鸟类和水貂（以及其他半水生哺乳动物），这种适应改变或不改变它们对禽类的感染性，但可以显著增加对人类和陆生哺乳动物的感染性。鸭，鹅等家禽可以通过与疫水接触而感染。在放养状态下，它将不可避免地导致包括人类在内的陆生栖息地流通，通过粪-口途径或呼吸道途径传播。.研究还以H7N9及H3N2为实例，探讨了甲型流感病毒实现跨物种传播所需跨越的嗜性相关位点的变异方式及相应条件，提出H7N9与H9N2和H5N1一样，日益成为甲型流感病毒新亚型的重配供体而非受体。