In view of the rapidly progressing COVID-19 pandemic, our aim was to isolate and characterize SARS-CoV-2 from Indian patients. SARS-CoV-2 was isolated from nasopharyngeal swabs collected from the two members of a family without any history of (H/O) travel abroad. Both the virus isolates (8003 and 8004) showed CPE on day 3 post-inoculation, viral antigens by immunofluorescence assay and produced distinct, clear and uniform plaques. Infectious virus titers were 5 × 10⁶ and 4 × 10⁶ Pfu/ml by plaque assay and 10^7.5 and 10⁷ by CPE-based TCID50/ml, respectively. Phylogenetic analysis grouped our isolates with the Italian strains. On comparison with Wuhan strain, 3 unique mutations were identified in nsp3 (A1812D), exonuclease (P1821S) of Orf1ab and spike protein (Q677H) regions, respectively. Both the viruses grouped with Italian strains of SARS-CoV-2 suggesting possible source being the virus imported from Italy. These fully characterized virus isolates will be useful in developing neutralization/virological assays for the evaluation of vaccines/antivirals.

鉴于迅速发展的 COVID-19 大流行，我们的目标是从印度患者中分离和表征 SARS-CoV-2。SARS-CoV-2 是从一个没有任何 (H/O) 出国旅行史的家庭的两名成员采集的鼻咽拭子中分离出来的。两种病毒分离物（8003 和 8004）在接种后第 3 天显示 CPE，通过免疫荧光测定显示病毒抗原，并产生明显、清晰和均匀的斑块。通过噬斑测定，传染性病毒滴度为 5 × 10 ⁶和 4 × 10 ⁶ Pfu/ml，10 ^7.5和 10 ⁷分别通过基于 CPE 的 TCID50/ml。系统发育分析将我们的分离株与意大利菌株分组。与武汉株相比，分别在Orf1ab的nsp3（A1812D）、核酸外切酶（P1821S）和刺突蛋白（Q677H）区域鉴定出3个独特突变。这两种病毒都与意大利的 SARS-CoV-2 毒株分组，这表明可能的来源是从意大利进口的病毒。这些完全表征的病毒分离物将有助于开发用于评估疫苗/抗病毒药物的中和/病毒学分析。