Viral Research Division, National Veterinary Research Institute, Vom, Nigeria.
Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany.
Transbound Emerg Dis. 2019 Jul;66(4):1631-1641. doi: 10.1111/tbed.13197. Epub 2019 Apr 23.
Capripox virus infections are endemic diseases of livestock in Nigeria, but there are limited data on molecular characterization of circulating viruses. In this study, we investigated field outbreaks of Capripox virus infections in Nigeria via partial sequencing of viruses obtained from field samples. Eleven selected samples, collected from 2000-2016 from cattle (9), sheep (1) and goat (1) in three states in Nigeria and Capripox virus genome positive by PCR and real-time qPCR, were characterized using our newly developed partial sequencing protocol. This method for genetic characterization of Capripox virus strains allows a first, short molecular classification of strains responsible for the investigated field outbreaks in the country. Phylogenetically, the eight LSDV samples obtained from 2010 to 2016 are closely related to already published strains occurring in Greece and Serbia in the years 2015 and 2016, respectively, whereas the isolate from 2000 shows high similarity to the South African NI-2490 strain. These data indicate that there was a change of LSDV strains circulating in Nigeria between the years 2000 and 2010. The samples isolated from a goat and a sheep in different years seem to be related to already known GTPV strains, but clearly differ from all current published GTPV strains. Interestingly, both newly detected GTPV strains show up to 100% similarity compared to each other and led to clinical disease in sheep and goats. It is long known that some strains of GTPV and SPPV are able to infect both sheep and goats, but in most cases lead to more severe disease in only one of these species. Further genetic characterization of these isolates could provide more insight into pathogenesis and virulence factors of Capripox viruses, especially GTPV and SPPV.
羊痘病毒感染是尼日利亚牲畜的地方性疾病，但关于循环病毒的分子特征描述数据有限。在本研究中，我们通过对从现场样本中获得的病毒进行部分测序，调查了尼日利亚的羊痘病毒感染田间暴发。从 2000 年至 2016 年，从尼日利亚三个州的牛（9 只）、绵羊（1 只）和山羊（1 只）中采集了 11 个选定样本，这些样本通过 PCR 和实时 qPCR 检测为 Capripox 病毒基因组阳性，并用我们新开发的部分测序方案对其进行了特征描述。这种羊痘病毒株的遗传特征分析方法允许对该国调查的田间暴发中负责的株系进行首次简短的分子分类。从 2010 年至 2016 年获得的 8 个 LSDV 样本在系统发育上与分别于 2015 年和 2016 年在希腊和塞尔维亚发现的已发表株系密切相关，而 2000 年的分离株与南非的 NI-2490 株具有高度相似性。这些数据表明，2000 年至 2010 年间，在尼日利亚循环的 LSDV 株发生了变化。在不同年份从一只山羊和一只绵羊中分离的样本似乎与已知的 GTPV 株有关，但与所有当前已发表的 GTPV 株明显不同。有趣的是，这两种新检测到的 GTPV 株彼此之间的相似度高达 100%，并导致绵羊和山羊发生临床疾病。长期以来，人们一直知道，GTPV 和 SPPV 的一些株系能够感染绵羊和山羊，但在大多数情况下，只会导致其中一种物种出现更严重的疾病。对这些分离株进行进一步的遗传特征描述可以更深入地了解羊痘病毒，尤其是 GTPV 和 SPPV 的发病机制和毒力因子。
