Department of Veterinary Pathology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
University of Helsinki, Faculty of Medicine, Medicum, Department of Virology, Helsinki, Finland
J Virol. 2020 May 18;94(11). doi: 10.1128/JVI.00001-20.
Boid inclusion body disease (BIBD) is a transmissible viral disease of captive snakes that causes severe losses in snake collections worldwide. It is caused by reptarenavirus infection, which can persist over several years without overt signs but is generally associated with the eventual death of the affected snakes. Thus far, reports have confirmed the existence of reptarenaviruses in captive snakes in North America, Europe, Asia, and Australia, but there is no evidence that it also occurs in wild snakes. BIBD affects boa species within the subfamily and pythons in the family , the habitats of which do not naturally overlap. Here, we studied Brazilian captive snakes with BIBD using a metatranscriptomic approach, and we report the identification of novel reptarenaviruses, hartmaniviruses, and a new species in the family The reptarenavirus L segments identified are divergent enough to represent six novel species, while we found only a single novel reptarenavirus S segment. Until now, hartmaniviruses had been identified only in European captive boas with BIBD, and the present results increase the number of known hartmaniviruses from four to six. The newly identified chuvirus showed 38.4%, 40.9%, and 48.1% amino acid identity to the nucleoprotein, glycoprotein, and RNA-dependent RNA polymerase, respectively, of its closest relative, Guangdong red-banded snake chuvirus-like virus. Although we cannot rule out the possibility that the found viruses originated from imported snakes, the results suggest that the viruses could circulate in indigenous snake populations. Boid inclusion body disease (BIBD), caused by reptarenavirus infection, affects captive snake populations worldwide, but the reservoir hosts of reptarenaviruses remain unknown. Here, we report the identification of novel reptarenaviruses, hartmaniviruses, and a chuvirus in captive Brazilian boas with BIBD. Three of the four snakes studied showed coinfection with all three viruses, and one of the snakes harbored three novel reptarenavirus L segments and one novel S segment. The samples originated from collections with Brazilian indigenous snakes only, which could indicate that these viruses circulate in wild snakes. The findings could further indicate that boid snakes are the natural reservoir of reptarena- and hartmaniviruses commonly found in captive snakes. The snakes infected with the novel chuvirus all suffered from BIBD; it is therefore not possible to comment on its potential pathogenicity and contribution to the observed changes in the present case material.
蟒蚺包涵体病（BIBD）是一种可传染的蛇类病毒性疾病，导致全球蛇类收藏遭受严重损失。它由 reptarenavirus 感染引起，这种病毒可以潜伏多年而没有明显症状，但通常与受感染蛇类的最终死亡有关。迄今为止，报告已证实北美、欧洲、亚洲和澳大利亚的圈养蛇类中存在 reptarenaviruses，但没有证据表明它也存在于野生蛇类中。BIBD 影响蟒蚺亚科和蚺科的蟒蛇，它们的栖息地不会自然重叠。在这里，我们使用宏转录组学方法研究了患有 BIBD 的巴西圈养蛇类，并报告了新型 reptarenaviruses、hartmaniviruses 和家族中的一个新物种。鉴定的 reptarenavirus L 片段差异足够大，足以代表六个新物种，而我们只发现了一个新型 reptarenavirus S 片段。到目前为止，hartmaniviruses 仅在患有 BIBD 的欧洲圈养蟒中被鉴定出来，而目前的结果将已知的 hartmaniviruses 数量从四个增加到六个。新鉴定的 chuvirus 与最接近的近亲广东红带蛇 chuvirus-like virus 的核蛋白、糖蛋白和 RNA 依赖性 RNA 聚合酶分别具有 38.4%、40.9%和 48.1%的氨基酸同一性。尽管我们不能排除发现的病毒源自进口蛇类的可能性，但结果表明这些病毒可能在本土蛇类种群中传播。由 reptarenavirus 感染引起的蟒蚺包涵体病（BIBD）影响着全球的圈养蛇类种群，但 reptarenaviruses 的储存宿主仍不清楚。在这里，我们报告了在患有 BIBD 的巴西圈养蟒中发现的新型 reptarenaviruses、hartmaniviruses 和 chuvirus。所研究的 4 条蛇中有 3 条显示出这三种病毒的混合感染，其中一条蛇携带了 3 个新型 reptarenavirus L 片段和 1 个新型 S 片段。这些样本来自仅包含巴西本土蛇类的收藏，这可能表明这些病毒在野生蛇类中传播。这些发现可能进一步表明，蟒蚺是常见于圈养蛇类中的 reptarena- 和 hartmaniviruses 的天然宿主。感染新型 chuvirus 的蛇都患有 BIBD；因此，无法对其潜在的致病性及其对目前病例材料中观察到的变化的贡献进行评论。
