Rooting the Phylogenetic Tree of Middle East Respiratory Syndrome Coronavirus by Characterization of a Conspecific Virus from an African Bat
Rooting the Phylogenetic Tree of Middle East Respiratory Syndrome Coronavirus by Characterization of a Conspecific Virus from an African Bat
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DOI：
10.1128/jvi.01498-14
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发表时间：
2014-10-01
影响因子：
5.4
通讯作者：
Drexler, Jan Felix
中科院分区：
文献类型：
--
作者：
Corman, Victor Max;Ithete, Ndapewa Laudika;Drexler, Jan Felix
新出现的中东呼吸综合征冠状病毒主要在阿拉伯半岛引起致命的呼吸道感染。MERS-CoV的进化起源尚不清楚。我们直接从南非Neoromicia capensis蝙蝠（NeoCoV）获得的粪便材料中确定了CoV的全基因组序列。NeoCoV与MERS-CoV共享基因组结构的基本细节。NeoCoV基因组的85%在核苷酸水平上与MERS-CoV相同。根据分类学标准，NeoCoV和MERS-CoV属于一个病毒种。在NeoCoV刺突基因内存在遗传上不同的S1亚基，表明刺突内重组事件可能参与了MERS-CoV的出现。NeoCoV构成MERS-CoV的姐妹分类群，将MERS-CoV的根置于最近描述的来自非洲骆驼的病毒和所有其他病毒之间。这表明骆驼中的病毒多样性水平高于人类。再加上20年前在非洲和阿拉伯半岛采样的骆驼科动物中广泛感染MERS-CoV的血清学证据，遗传数据表明骆驼是人类的病毒来源，而不是相反。阿拉伯半岛的大部分骆驼是从非洲之角进口的，那里有几种新骆驼。骆驼从蝙蝠那里获得MERS-CoV可能发生在撒哈拉以南非洲。骆驼科动物可能代表MERS-CoV和其他哺乳动物CoV的混合容器。重要信息目前还不清楚高致病性MERS-CoV是如何、何时和何地出现的。我们表征了与MERS-CoV密切相关的非洲蝙蝠病毒的全基因组，并表明人类，骆驼和蝙蝠病毒属于相同的病毒物种。蝙蝠病毒是中东呼吸综合征冠状病毒系统发育树的根源，为中东呼吸综合征冠状病毒在骆驼中的进化先于人类进化提供了证据。修订后的树表明，人类是被骆驼感染的，而不是相反。虽然中东呼吸综合征冠状病毒病例主要发生在阿拉伯半岛，但本研究的数据以及对非洲骆驼的血清学和分子学研究表明，最初的宿主转换可能发生在非洲。MERS-CoV的出现可能涉及不同病毒祖先之间的遗传元件交换。这些交换可能发生在蝙蝠祖先或骆驼身上，骆驼充当不同宿主病毒的混合容器。
The emerging Middle East respiratory syndrome coronavirus (MERS-CoV) causes lethal respiratory infections mainly on the Arabian Peninsula. The evolutionary origins of MERS-CoV are unknown. We determined the full genome sequence of a CoV directly from fecal material obtained from a South African Neoromicia capensis bat (NeoCoV). NeoCoV shared essential details of genome architecture with MERS-CoV. Eighty-five percent of the NeoCoV genome was identical to MERS-CoV at the nucleotide level. Based on taxonomic criteria, NeoCoV and MERS-CoV belonged to one viral species. The presence of a genetically divergent S1 subunit within the NeoCoV spike gene indicated that intraspike recombination events may have been involved in the emergence of MERS-CoV. NeoCoV constitutes a sister taxon of MERS-CoV, placing the MERS-CoV root between a recently described virus from African camels and all other viruses. This suggests a higher level of viral diversity in camels than in humans. Together with serologic evidence for widespread MERS-CoV infection in camelids sampled up to 20 years ago in Africa and the Arabian Peninsula, the genetic data indicate that camels act as sources of virus for humans rather than vice versa. The majority of camels on the Arabian Peninsula is imported from the Greater Horn of Africa, where several Neoromicia species occur. The acquisition of MERS-CoV by camels from bats might have taken place in sub-Saharan Africa. Camelids may represent mixing vessels for MERS-CoV and other mammalian CoVs.IMPORTANCEIt is unclear how, when, and where the highly pathogenic MERS-CoV emerged. We characterized the full genome of an African bat virus closely related to MERS-CoV and show that human, camel, and bat viruses belong to the same viral species. The bat virus roots the phylogenetic tree of MERS-CoV, providing evidence for an evolution of MERS-CoV in camels that preceded that in humans. The revised tree suggests that humans are infected by camels rather than vice versa. Although MERS-CoV cases occur mainly on the Arabian Peninsula, the data from this study together with serologic and molecular investigations of African camels indicate that the initial host switch from bats may have taken place in Africa. The emergence of MERS-CoV likely involved exchanges of genetic elements between different viral ancestors. These exchanges may have taken place either in bat ancestors or in camels acting as mixing vessels for viruses from different hosts.