FIG 1.

Susceptibility and replication properties of the SARS-CoV-2 in deer cells in vitro. (A) Deer lung (DL), Vero E6, and Vero E6/TMPRSS2 cells were inoculated with SARS-CoV-2 at a multiplicity of infection (MOI) of 1. At 24 h postinoculation (hpi), cells were fixed and subjected to an immunofluorescence assay using a monoclonal antibody (MAb) anti-ACE2 (green) and with a MAb anti-SARS-CoV-2-nucleoprotein (N) (red). Nuclear counterstain was performed with DAPI (blue); ×40 magnification. (B) To assess the kinetics of replication of SARS-CoV-2, DL, Vero E6, and Vero E6/TMPRSS2 cells were inoculated with SARS-CoV-2 isolate TGR/NY/20 (MOI of 0.1 and 1) and harvested at various time points postinoculation (12, 24, 36, 48, and 72 hpi; time zero shown in the graphs represent the back titration of input virus). Virus titers were determined on each time point using endpoint dilutions and the Spearman and Karber's method and expressed as log₁₀ ${\mathrm{TCID}}_{50}·{\text{ml}}^{-1}$. Results represent the average of three independent experiments.