关键词： Diseases   Ecology  

摘要： Marburg virus (MARV) causes sporadic outbreaks of severe Marburg virus disease (MVD). Most MVD outbreaks originated in East Africa and field studies in East Africa, South Africa, Zambia, and Gabon identified the Egyptian rousette bat (ERB;Rousettus aegyptiacus) as a natural reservoir. However, the largest recorded MVD outbreak with the highest case-fatality ratio happened in 2005 in Angola, where direct spillover from bats was not shown. Here, collaborative studies by the Centers for Disease Control and Prevention, Njala University, University of California, Davis USAID-PREDICT, and the University of Makeni identify MARV circulating in ERBs in Sierra Leone. PCR, antibody and virus isolation data from 1755 bats of 42 species shows active MARV infection in approximately 2.5% of ERBs. Phylogenetic analysis identifies MARVs that are similar to the Angola strain. These results provide evidence of MARV circulation in West Africa and demonstrate the value of pathogen surveillance to identify previously undetected threats.

关键词： 正噬肝病毒   进化模式   蝙蝠噬肝病毒   鼩鼱噬肝病毒  

摘要： 正噬肝病毒属于噬肝病毒科，宿主为哺乳动物。该病毒被大家所熟知，是因为感染人的正噬肝病毒(HBV)是威胁全球人类健康的传染病病原体，它感染了超过三分之一的世界人口，每年导致至少887，000死亡。此外，正噬肝病毒除了能够感染包括人在内的灵长类动物外，也能感染松鼠科啮齿类动物和蝙蝠。值得注意的是，在美洲发现的能够感染筑帐蝠(tent-making bat)的一株正噬肝病毒(TBHBV)具有感染人的肝细胞的能力，提示了HBV的野生动物起源的可能性。有意思的是，三株松鼠科中发现的噬肝病毒、TBHBV以及唯一一株在进化上形成单支并处于其他灵长类噬肝病毒外围的非人类灵长类病毒(WMHBV,woolly monkey hepatitis B virus)均是在新大陆发现的，因此，有研究者提出了正噬肝病毒新大陆起源的观点。然而，由于目前所知正噬肝病毒的宿主有限，所以对于正噬肝病毒的起源进化并不明确。\n 因此，为了更好的研究正噬肝病毒的多样性、宿主范围及进化史，选择了与人类关系密切的翼手目（蝙蝠）、啮齿目（老鼠）及食虫目（鼩鼱）三种小型哺乳动物进行筛查研究。这三种哺乳动物种类丰富且数量繁多，约占哺乳动物的70％，是多种病原体的自然宿主，如SARS冠状病毒、出血热病原体汉坦病毒、拉萨热病毒、埃博拉病毒等，具有代表性，且对人类危害较大。\n 首先在贵州省、河南省、浙江省及湖北省分别采集了翼手目（蝙蝠）、啮齿类（老鼠）及食虫目（鼩鼱）等小型哺乳动物进行样本采集。之后，针对正噬肝病毒的保守区域，设计可以覆盖整个病毒属的通用引物，建立筛查体系，并对采集的样本进行筛查。在蝙蝠中检测到了遗传多样的噬肝病毒，总阳性率为13.3％(106/797);在597只鼩鼱中检测到了8只阳性个体，阳性率为1.3％(8/597)，此种病毒与已知噬肝病毒差异较大;然而，在数量和种类最多的啮齿类中却并没有检测到阳性样本。\n 在基因组扩增的基础上，对新发现的正噬肝病毒进行了遗传进化分析，结果显示新发现的蝙蝠噬肝病毒主要在进化树上分为两支，一支与在中国云南和缅甸发现聚集在一起，另外一支与在西非加蓬发现的两株病毒聚集在一起，说明蝙蝠与其携带的正噬肝病毒之间的相互作用具有较长的历史;在鼩鼱中发现的正噬肝病毒与在美洲筑帐蝠中发现的噬肝病毒(TBHBV)聚集在一起，处于整个噬肝病毒属根部的位置。此外，新发现的鼩鼱噬肝病毒相互之间的基因组核苷酸同源性在88％以上，说明为同一个病毒种，但是这种病毒却同时在三种鼩鼱中检测到，并且在地理距离比较远(＞1200km)的两个采样点被发现，这说明鼩鼱中的噬肝病毒在其体内也经历了较长的时间。鼩鼱噬肝病毒的发现及其在进化树中的位置也为正噬肝病毒的旧大陆起源提供了新证据。\n 为了进一步研究正噬肝病毒与其宿主的关系，进行了病毒与宿主的共进化分析，结果表明，正噬肝病毒的整体进化呈现共进化的趋势，在宿主目的水平上具有宿主特异性，在宿主科/属/种的水平上跨种间传播事件频繁发生。同时，进化树分析表明，蝙蝠和鼩鼱噬肝病毒还具有一定的原位进化特点。说明正噬肝病毒的进化是复杂的、历史久远的，不能仅用单一的进化事件解释，并且其地理及宿主起源也有待进一步调查，需要更多的新大陆和旧大陆其他哺乳类动物中噬肝病毒的研究证据。\n 综上所述，本研究发现蝙蝠携带的噬肝病毒具有很高的多样性，且首次证明鼩鼱是噬肝病毒的重要宿主，为正噬肝病毒的地理及宿主起源提供了新证据。正噬肝病毒与宿主存在明显的共进化特征，其与宿主长期相互作用并发生过频繁的跨种属传播。

关键词： Nipah virus   henipavirus   emerging infection   Pteropus bats   fruit bats   spillover   phylogenetic analysis   sequencing   animal model   hamster   Cambodia   viruses   zoonoses   pathogenicity   NiV-Malaysia genotype   CSUR381   phosphoprotein   Pteropus lylei  

摘要： We conducted an in-depth characterization of the Nipah virus (NiV) isolate previously obtained from a Pteropus lylei bat in Cambodia in 2003 (CSUR381). We performed full-genome sequencing and phylogenetic analyses and confirmed CSUR381 is part of the NiV-Malaysia genotype. In vitro studies revealed similar cell permissiveness and replication of CSUR381 (compared with 2 other NiV isolates) in both bat and human cell lines. Sequence alignments indicated conservation of the ephrin-B2 and ephrin-B3 receptor binding sites, the glycosylation site on the G attachment protein, as well as the editing site in phosphoprotein, suggesting production of nonstructural proteins V and W, known to counteract the host innate immunity. In the hamster animal model, CSUR381 induced lethal infections. Altogether, these data suggest that the Cambodia bat-derived NiV isolate has high pathogenic potential and, thus, provide insight for further studies and better risk assessment for future NiV outbreaks in Southeast Asia.

关键词： bioinformatics   phyloinformatics   community ecology   disease biology   metagenomics  

摘要： The spillover of viruses from wildlife into agricultural animals or humans has profound socioeconomic and public health impact. Vampire bats, found throughout South America, feed directly on humans and other animals and are an important reservoir for zoonotic viruses, including rabies virus. This has resulted in considerable effort in understanding both the ecology of bat-borne viruses and the composition and associated correlates of the structure of entire virus communities in wildlife, particularly in the context of disease control interventions. In a From the Cover article in this issue of Molecular Ecology, Bergner et al. (2019) set out to reveal virus community dynamics in vampire bats by interrogating factors that affect the structure, diversity and richness of these communities. Due to the linkage of metagenomic sequence data with community ecology, this study represents an important advance in the field of virus ecology.

关键词： African rainforests   biogeography   deforestation   emerging infectious diseases   favourability modelling   Pteropodidae   zoonosis  

摘要： A significant link between forest loss and fragmentation and outbreaks of Ebola virus disease (EVD) in humans has been documented. Deforestation may alter the natural circulation of viruses and change the composition, abundance, behaviour and possibly viral exposure of reservoir species. This in turn might increase contact between infected animals and humans. Fruit bats of the family Pteropodidae have been suspected as reservoirs of the Ebola virus. At present, the only evidence associating fruit bats with EVD is the presence of seropositive individuals in eight species and polymerase chain reaction-positive individuals in three of these. Our study investigates whether human activities can increase African fruit bat geographical ranges and whether this influence overlaps geographically with EVD outbreaks that, in turn, are favoured by deforestation. We use species observation records for the 20 fruit bat species found in favourable areas for the Ebola virus to determine factors affecting the bats' range inside the predicted Ebola virus area. We do this by employing a hypothetico-deductive approach based on favourability modelling. We show that the range of some fruit bat species is linked to human activities within the favourable areas for the Ebola virus. More specifically, the areas where human activities favour the presence of five fruit bat species overlap with the areas where EVD outbreaks in humans were themselves favoured by deforestation. These five species are as follows: Eidolon helvum, Epomops franqueti, Megaloglossus woermanni, Micropteropus pusillus and Rousettus aegyptiacus. Of these five, all but Megaloglossus woermanni have recorded seropositive individuals. For the remaining 15 bat species, we found no biogeographical support for the hypothesis that positive human influence on fruit bats could be associated with EVD outbreaks in deforested areas within the tropical forest biome in West and Central Africa. Our work is a useful first step allowing fur

关键词： Rabies   Livestock   Vampire bat   Desmodus rotundas   Network   Surveillance  

摘要： The importance of the common vampire bat Desmodus rotundus for the transmission of the rabies virus does not lie solely in its ability to transmit this disease to other mammals, but also in its capacity to adapt to environmental and climatic changes, granting them a wide geographical distribution. Control of this disease is currently based on culling of the vampire bat and vaccination of the livestock. A transmission model incorporating geographic and behavioral determinants of the vampire bat was proposed to direct and optimize the epidemiological surveillance and control of livestock rabies. This model was built using a bimodal network connecting 260 vampire bat roosts among themselves (roost-roost-network) and with 1557 farms (roost-farm network) in eastern Sao Paulo State, Brazil. These roosts were grouped in 9 communities, some very interconnected, and some not and the farms were grouped in 14 communities. From 2013 to 2017, 44 livestock rabies outbreaks occurred in the area, circulating among the farm communities during the entire period, with possible introductions from neighboring areas. Based on the network and environment parameters, it was possible to reasonably predict both the roosts' occupation type (harem, bachelor, overnight and empty) and livestock rabies outbreak occurrence. The network approach brings light to the importance of phylogenetic studies of bats and rabies virus. Finally, the understanding of the interactions between bats and their feeding sources, influenced by the environment, allows to establish more precise surveillance and control measures and, ultimately, with a lower cost-benefit ratio of these actions.

关键词： 哺乳动物   免疫系统  

摘要： 今年春节,新冠肺炎的阴霾笼罩在中国上空,整个世界一片低沉。科研人员研究发现,新型冠状病毒的来源很大可能为中华菊头蝠,它们也是2003年SARS病毒的源头宿主,而源起阿拉伯半岛的MERS(中东呼吸综合症)也是来自蝙蝠的冠状病毒。啮齿类动物、灵长类动物以及鸟类都会携带可能或已经传染给人类的疾病,但独具一格的蝙蝠却是所有携带病毒动物中的"佼佼者"。蝙蝠被称为天然的病毒储

关键词： 蝙蝠携带病毒   基因组学   基因特征  

摘要： 研究目的:　　了解云南省普洱地区蝙蝠病毒组成以及潜在致病性病毒，这有利于为突发病毒性公共卫生事件提供基础的数据支持;发现与鉴定新型病毒，为可能的跨宿主传播提供预警信息;更新蝙蝠所携带病毒的宿主种类和地理范围，扩展蝙蝠携带的病毒谱;对发现的新病毒进行基因组特点分析、系统进化分析和流行病学调查，为防治新病毒引起的疾病提供理论支撑。　　研究方法:　　收集我国云南省普洱地区蝙蝠标本，将蝙蝠肠道内容物和心脏、肝脏、肺脏、脑内容物分别混合为样本库;将上述样本库依次采用过滤、DNA酶消化的方法对标本进行处理并提取核酸;将提取的核酸送至诺禾基因科技股份有限公司进行Hiseq高通量测序;利用实验室建立好的生物信息分析平台对测序后的海量数据进行组分析，获得蝙蝠肠道内容物和组织的病毒组成;筛选出部分可能对人类或动物具有感染性的病毒进行PCR验证和全基因扩增并进行筛查，了解该病毒在蝙蝠中的分子流行病学特征;对潜在的新病毒，采用PCR方法、walkingPCR以及3'和5'RACE等方法扩增病毒全基因组以了解其基因组特点、进化关系等。　　研究结果:　　测序获得2019年云南普洱地区蝙蝠标本库高通量数据，序列经生物信息学分析后获得病毒注释报告，肠道内容物和组织标本库共有19,543条序列被注释到病毒。序列分析后发现肠道内容物标本序列划分为47个科和11个属，包括脊椎动物病毒有20个科47个属，植物病毒包括9个科15个属，无脊椎动物7个科15个属，另外噬菌体含有11个科34个属。脊椎动物病毒中包含多个具有公共卫生学意义的人兽共患病毒，有冠状病毒科甲型冠状病毒属、乙型冠状病毒属;杯状病毒科中的诺如病毒属和札如病毒属;呼肠弧病毒科的中轮状病毒属;星状病毒科中的哺乳动物星状病毒属;小RNA病毒科中的肠道病毒属和萨佩洛病毒属，细小病毒科中的博卡病毒属等，其中蝙蝠携带10.26%(4/39)的冠状病毒,并命名为Bat-Coronavirus/YN/2019。经过初步的基因重组预测，Bat-Coronavirus/YN/2019没有重组的现象。Bat-Coronavirus/YN/2019系统进化分析显示，Bat-Coronavirus/YN/2019与HKU2、来自于云南的中华菊头蝠的冠状病毒以及多株PEAV有较近的亲缘关系。　　2016年云南普洱地区的3.75%(3/84)的蝙蝠携带乙肝病毒，均来自于中华菊头蝠，命名为PuErBHBV。PuErBHBV的基因结构、保守功能结构域与其他乙肝病毒高度相似。序列分析显示PuErBHBV与河南内乡发现的NeiXiang-Rp-89的核苷酸和氨基酸同源性分别为87.1%和90.5%。系统进化分析显示，蝙蝠乙肝病毒呈现丰富的多样性，可分为两个较远的进化分支。同时，PuErBHBV与贵州、河南内乡蝙蝠携带乙肝病毒具有最近的亲缘关系，但与巴拿马的TBHBV处在不同的进化分支。PuErBHBV是一株新的蝙蝠乙肝病毒株，病毒在不同蝠种之间的传播和地域差别可能共同促进了蝙蝠乙肝病毒的进化，本研究丰富了蝙蝠乙肝病毒的多样性。　　研究结论:　　本研究通过病毒宏基因组学方法发现我国云南省蝙蝠携带病毒种类繁多，存在大量可能对动物和人类致病的病毒，也发现了大量与已知病毒相似性较低的病毒，如冠状病毒、轮状病毒、札如病毒和诺如病毒等，丰富了我国及全球野生动物携带病毒数据库。发现一株新的蝙蝠乙肝病毒PuErBHBV,病毒在不同蝠种之间的传播和地域差别可能共同促进了蝙蝠乙肝病毒的进化和多样性。

摘要： 一项最新病毒学研究显示,新冠病毒或在40年至70年前从与之关系最紧密的蝙蝠病毒中分化出来,其意味着产生新冠病毒的病毒谱系,可能已经在蝙蝠中传播几十年了。蝙蝠病毒Ra TG13被鉴定为与新冠病毒关系最密切,同时提示新冠病毒爆发可能源于蝙蝠。但是,研究人员也在穿山甲体内发现了相似的冠状病毒,有观点认为,穿山甲可能是中间宿主。

摘要： 对于人类来说,蝙蝠既熟悉又陌生。它们昼伏夜出,神秘诡异,而且还与人类的健康有着千丝万缕的联系,比如,SARS(非典)、埃博拉等传染病也都可能源于蝙蝠所携带的病毒。那么,相比其他野生动物,蝙蝠体内的病毒多得吓人。这是为什么呢?蝙蝠为何那么"毒"科学家要追溯源头,才能更好地战胜病毒。在追溯人畜共患疾病的过程中,科学家发现蝙蝠的确是动物界的"病毒王",堪称"大自然中移动的病毒库"。蝙蝠是一种奇特的哺乳动物,是世界上唯一能长时间飞翔的哺乳动物。或许是与众不同的生活习性,它们很难融入其他哺乳动物的生活圈中,而是隐匿地生活着。