Díaz Francisco J, Aguilar-Jiménez Wbeimar, Flórez-Álvarez Lizdany, Valencia Gladys, Laiton-Donato Katherine, Franco-Muñoz Carlos, Álvarez-Díaz Diego, Mercado-Reyes Marcela, Rugeles María Teresa
Grupo de Inmunovirología, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
Ayudas Diagnósticas de Laboratorio Clínico, ADILAB, Medellín, Colombia.
Biomedica. 2020 Oct 30;40(Supl. 2):148-158. doi: 10.7705/biomedica.5834.
Introduction: SARS-CoV-2 has been identified as the new coronavirus causing an outbreak of acute respiratory disease in China in December, 2019. This disease, currently named COVID-19, has been declared as a pandemic by the World Health Organization (WHO). The first case of COVID-19 in Colombia was reported on March 6, 2020. Here we characterize an early SARS-CoV-2 isolate from the pandemic recovered in April, 2020. Objective: To describe the isolation and characterization of an early SARS-CoV-2 isolate from the epidemic in Colombia. Materials and methods: A nasopharyngeal specimen from a COVID-19 positive patient was inoculated on different cell lines. To confirm the presence of SARS-CoV-2 on cultures we used qRT-PCR, indirect immunofluorescence assay, transmission and scanning electron microscopy, and next-generation sequencing. Results: We determined the isolation of SARS-CoV-2 in Vero-E6 cells by the appearance of the cytopathic effect three days post-infection and confirmed it by the positive results in the qRT-PCR and the immunofluorescence with convalescent serum. Transmission and scanning electron microscopy images obtained from infected cells showed the presence of structures compatible with SARS-CoV-2. Finally, a complete genome sequence obtained by next-generation sequencing allowed classifying the isolate as B.1.5 lineage. Conclusion: The evidence presented in this article confirms the first isolation of SARSCoV-2 in Colombia. In addition, it shows that this strain behaves in cell culture in a similar way to that reported in the literature for other isolates and that its genetic composition is consistent with the predominant variant in the world. Finally, points out the importance of viral isolation for the detection of neutralizing antibodies, for the genotypic and phenotypic characterization of the strain and for testing compounds with antiviral potential.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）已被确定为2019年12月在中国引发急性呼吸道疾病暴发的新型冠状病毒。这种疾病目前被命名为冠状病毒病2019（COVID-19），已被世界卫生组织（WHO）宣布为大流行病。2020年3月6日，哥伦比亚报告了首例COVID-19病例。在此，我们对2020年4月从该大流行中分离出的一株早期SARS-CoV-2进行了特征描述。目的：描述从哥伦比亚疫情中分离出的一株早期SARS-CoV-2的分离及特征。材料与方法：将一名COVID-19阳性患者的鼻咽标本接种于不同细胞系。为确认培养物中是否存在SARS-CoV-2，我们使用了定量逆转录聚合酶链反应（qRT-PCR）、间接免疫荧光测定、透射和扫描电子显微镜以及下一代测序技术。结果：感染三天后，通过细胞病变效应的出现，我们确定在非洲绿猴肾细胞（Vero-E6）中分离出了SARS-CoV-2，并通过qRT-PCR阳性结果以及康复期血清免疫荧光结果进行了确认。从感染细胞获得的透射和扫描电子显微镜图像显示存在与SARS-CoV-2相符的结构。最后，通过下一代测序获得的完整基因组序列使该分离株被归类为B.1.5谱系。结论：本文提供的证据证实了在哥伦比亚首次分离出SARS-CoV-2。此外，研究表明该毒株在细胞培养中的表现与文献中报道的其他分离株相似，且其基因组成与全球主要变体一致。最后，指出了病毒分离对于检测中和抗体、菌株的基因型和表型特征鉴定以及测试具有抗病毒潜力的化合物的重要性。
