Epidemiological Analysis From 2018 to 2020 in China and Prevention Strategy of Porcine Circovirus Type 2

Figures

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  Figure 1. PCR identification results of some positive samples. 1, DNA molecular size marker; 2–10, Partial positive samples; 11, Positive control; 12, Negative control. Arrow indicates the position of the predicted DNA size.

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  Figure 2. Identity analysis of partial sequences from PCV2 ORF2 gene.

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  Figure 3. Multiple sequence alignment of ORF2-encoded Cap protein amino acids of some strains. Epitopes are boxed.

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  Figure 4. Phylogenetic tree based on 82 PCV2 nucleotide sequences, including the 62 samples obtained in this study (not marked) and 20 strains of the different genotypes available from GenBank (PCV2a to PCV2e) (marked). The phylogenetic tree was constructed by the neighbor-joining method using the maximum composite likelihood model with MEGA v6 software.

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  Figure 5. Purified sample subjected to SDS-PAGE (A). TEM images of Bac-2bCap (B) and Bac-2dCap (C).

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  Figure 6. Homologous and heterologous immune response of PCV2d Cap protein against the PCV2b and PCV2dagainst the PCV2b and PCV2d. (A) Specific antibody levels for PCV2b and PCV2d Cap proteins at 0 dpc. (B) Detection of PCV2 DNA in serum by PCR at 14 dpc. (C) Detection of the PCV2 DNA load in serum by RT-PCR at 14 dpc. (D) Levels of IFN-γ in blood at 14 dpc. The data are presented as group mean optical density (MOD ± standard error). Significant differences are indicated by different superscripts (A–C) (p < 0.05). Data were analyzed using one-way analysis of variance with Dunnett's multiple comparisons test using GraphPad Prism 7 software (GraphPad Software, USA), ****p < 0.001.

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  Figure 7. Homologous and heterologous immune response of PCV2d Cap protein against the PCV2b and PCV2dagainst the PCV2b and PCV2d. (A) Specific antibody levels for PCV2b and PCV2d Cap proteins at 0 dpc. (B) Detection of PCV2 DNA in serum by PCR at 14 dpc. (C) Detection of the PCV2 DNA load in serum by RT-PCR at 14 dpc. (D) Levels of IFN-γ in blood at 14 dpc. The data are presented as group mean optical density (MOD ± standard error). Significant differences are indicated by different superscripts (A–C) (p < 0.05). Data were analyzed using one-way analysis of variance with Dunnett's multiple comparisons test using GraphPad Prism 7 software (GraphPad Software, USA), ****p < 0.001.