Fig. 2

Growth kinetics of different viruses in the A549, PK15 and DF1 cell lines A/Environment/Fujian/85144/2014, A/Brisbane/59/2007, A/duck/Alberta/1976, and A/swine/15/1930 were inoculated into the A549, DF1, and PK15 cell lines, respectively. The multiplicity of infection was 0.01. The supernatants were collected at 0, 12, 24, 36, 48, 60 and 72 h. The log₁₀TCID₅₀ was used to evaluate the viral load