Isolation and Identification of Severe Fever with Thrombocytopenia Syndrome Virus from Farmed Mink in Shandong, China

Figure 1

Identification of isolate SFTSV SD22-2 from mink. (a) Heat map showing the different viral reads in seven tissues of minks. Five families of viruses, Anelloviridae, Parvoviridae, Caliciviridae, Paramyxoviridae, and Phenuiviridae, are found in this study. (b) Phylogenetic analysis and genotype of SFTSV SD22-2 based on the partial L segment sequences (6,237 bp). A solid triangle marks isolated SFTSV SD22-2 in this study. Nucleotide sequences were analyzed using the NJ method and Maximum Composite Likelihood model in MEGA11. Bootstrap values were calculated on 1,000 replicates. (c) Electron microscopy of SFTSV SD22-2. The supernatant of infected Vero cells was placed directly onto a carbon grid and stained with 2% PTA, and the grid was examined at 80 KV using an HT7800 TEM. (d) Detection of the isolate of SD22-2 in DH82 cells by indirect immunofluorescence (IFA). Following 7 days of incubation, DH82 cells were immunostained by IFA using a polyclonal antibody specific for the NP protein of SFTSV and FITC-labeled goat antimouse IgG. (e) Detection of the NP protein by Western blot. At 3 days postinfection, the DH82 cells were lysed for Western blot analysis using anti-NP antibody. Mock was the normal DH82 cells, and SD22-2 P1 and P2 were the infected DH82 cells in passages 1 and 2, respectively.

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