Laboratorio de Virología Molecular, Centro de Microbiología y Biología Celular, Instituto Venezolano de Investigaciones Científicas, Caracas, Miranda, Venezuela.
Instituto Nacional de Higiene "Rafael Rangel", Caracas, Miranda, Venezuela.
PLoS One. 2021 Feb 19;16(2):e0247196. doi: 10.1371/journal.pone.0247196. eCollection 2021.
SARS-CoV-2 is the new coronavirus responsible for COVID-19 disease. The first two cases of COVID-19 were detected in Venezuela on March 13, 2020. The aim of this study was the genetic characterization of Venezuelan SARS-CoV-2 isolates. A total of 7 full SARS-CoV-2 genome sequences were obtained by Sanger sequencing, from patients of different regions of Venezuela, mainly from the beginning of the epidemic. Ten out of 11 isolates (6 complete genomes and 4 partial spike genomic regions) belonged to lineage B, bearing the D614G mutation in the Spike protein. Isolates from the first outbreak that occurred in the Margarita Island harbored an in-frame deletion in its sequence, without amino acids 83-85 of the NSP1 of the ORF1. The search for deletions in 48,635 sequences showed that the NSP1 gene exhibit the highest frequency of deletions along the whole genome. Structural analysis suggests a change in the N-terminal domain with the presence of this deletion. In contrast, isolates circulating later in this island lacked the deletion, suggesting new introductions to the island after this first outbreak. In conclusion, a high diversity of SARS-CoV-2 isolates were found circulating in Venezuela, with predominance of the D614G mutation. The first small outbreak in Margarita Island seemed to be associated with a strain carrying a small deletion in the NSP1 protein, but these isolates do not seem to be responsible for the larger outbreak which started in July.
SARS-CoV-2 是导致 COVID-19 疾病的新型冠状病毒。2020 年 3 月 13 日，委内瑞拉首次发现了两例 COVID-19 病例。本研究的目的是对委内瑞拉 SARS-CoV-2 分离株进行基因特征分析。通过 Sanger 测序共获得了 7 个全长 SARS-CoV-2 基因组序列，这些序列来自委内瑞拉不同地区的患者，主要来自疫情初期。11 个分离株中的 10 个（6 个完整基因组和 4 个 Spike 基因组部分区域）属于谱系 B，其 Spike 蛋白中带有 D614G 突变。在玛格丽塔岛首次爆发的疫情中，分离株的序列中存在一个框内缺失，缺失了 ORF1 的 NSP1 中 83-85 位氨基酸。对 48635 个序列中的缺失进行搜索发现，NSP1 基因在整个基因组中显示出最高频率的缺失。结构分析表明，该缺失导致 N 端结构域发生变化。相比之下，后来在该岛循环的分离株中没有缺失，表明在首次爆发后，该岛有新的输入。总之，在委内瑞拉发现了多种 SARS-CoV-2 分离株，其中 D614G 突变占主导地位。玛格丽塔岛的首次小型爆发似乎与携带 NSP1 蛋白小缺失的株系有关，但这些分离株似乎与 7 月开始的更大规模爆发无关。
