From 1993 to 1994, 64 free-ranging elephants (Loxodonta africana) succumbed to encephalomyocarditis in the Kruger National Park, South Africa, of which 83% were adult bulls. Mastomys rodents were implicated as the reservoir host of the Encephalomyocarditis virus (EMCV) based on serology and RT-PCR. However, in the absence of sequence-confirmation of both the virus and the rodent host, definitive links between the elephant outbreak strains and rodent reservoir could not be established. In this study, we generate the first reference genome sequences for three historical EMCVs isolated from two Mastomys rodents and one Mastomys-associated mite, Laelaps muricola, in Gauteng Province, South Africa, in 1961. In addition, near-complete genome sequences were generated for two elephant outbreak virus strains, for which data were previously limited to the P1 and 3D genome regions. The consensus sequence of each virus was determined using a PCR-Sanger sequencing approach. Phylogenetic analysis confirmed the three near-identical (99.95–99.97%) Mastomys-associated viruses to be sister to the two near-identical (99.85%) elephant outbreak strains, differing from each other at 6.4% of sites across the ~7400-nucleotide region characterised. This study demonstrates a link between Mastomys-associated viruses and the historical elephant outbreak strains and implicates Mastomys as reservoirs of EMCV in South Africa.

中文翻译：

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对南非历史性脑心肌炎病毒的基因组测序将历史上 1993/4 年稀树草原象 (Loxodonta africana) 的爆发与隐性乳鼠啮齿动物联系起来

1993年至1994年，南非克鲁格国家公园有64头自由放养的大象（Loxodonta africana）死于脑心肌炎，其中83%是成年公牛。根据血清学和 RT-PCR，乳鼠啮齿动物被认为是脑心肌炎病毒 (EMCV) 的储存宿主。然而，由于缺乏病毒和啮齿动物宿主的序列确认，无法确定大象暴发毒株和啮齿动物宿主之间的明确联系。在这项研究中，我们于 1961 年从南非豪登省的两种 Mastomys 啮齿动物和一种 Mastomys 相关螨 Laelaps muricola 中分离出三种历史 EMCV，生成了第一个参考基因组序列。此外，还生成了近乎完整的基因组序列两种大象暴发病毒株的数据以前仅限于 P1 和 3D 基因组区域。使用 PCR-Sanger 测序方法确定每种病毒的共有序列。系统发育分析证实，三种几乎相同 (99.95–99.97%) 的 Mastomys 相关病毒是两种几乎相同 (99.85%) 的大象暴发毒株的姐妹病毒，在约 7400 个核苷酸的位点上有 6.4% 的位点存在差异地区特色。这项研究证明了 Mastomys 相关病毒与历史上大象爆发毒株之间的联系，并表明 Mastomys 是南非 EMCV 的宿主。