Comparison of the Pathogenicity of Classical Swine Fever Virus Subgenotype 2.1c and 2.1d Strains from China

Figures

• 

  Figure 1. Identification of isolated CSFV strains. IFA of PK-15 cells infected with isolated CSFV strains at 36 h post-infection.

• 

  Figure 2. Phylogenetic analysis based on the full-length E2 gene of the isolated virus. Phylogenetic trees were constructed using MEGA 7.0.18 software with the neighbor-joining method (1000 bootstrap replicates). The isolated virus is marked in red.

• 

  Figure 3. Amino acid sequence analysis of E2 genes of the three CSFV isolates. The special sites of AA mutation of these isolates are marked as red boxes.

• 

  Figure 4. Comparison of the characteristics of the three CSFV isolates in PK15 cells. (A) One-step growth curves of the three CSFV isolates. (B) At 72 h post infection, the virus titers were determined in PK15 cells. Data represent the mean ± SEM from three independent experiments. * p < 0.05; ** p < 0.01.

• 

  Figure 5. Rectal temperatures (A), survival rates (B), clinical scores (C) and viremia levels (D) of the pigs infected with the three CSFV isolates. Virus titers in blood are expressed as the mean log10TCID50/mL. All data are expressed as mean ± SEM.

• 

  Figure 6. Hematological data of clinical samples from animals infected with the three new CSFV isolates. The leukocyte numbers (A) and platelet counts (B) are expressed as numbers/L of blood. Data are presented as the mean ± SEM.