TABLE 2.
Characteristics of infection with four challenge strainsa
| Group | Macroscopic pneumonia (%) | Microscopic lung scores (0–22) | Microscopic trachea scores (0–8) | BALF virus titer (log10 TCID50) |
|---|---|---|---|---|
| Control | 0.2 ± 0.1b | 0.0 ± 0.0b | 0.0 ± 0.0b | 0.0 ± 0.0b |
| wtNC/19-pdmNP | 6.4 ± 1.4d | 6.4 ± 0.7c | 3.3 ± 0.5c | 4.1 ± 0.3c |
| NC/19-trigNP | 5.0 ± 0.6cd | 6.3 ± 1.0c | 3.7 ± 0.4c | 5.4 ± 0.2d |
| wtMN/18-trigNP | 3.6 ± 0.6bcd | 6.0 ± 0.6c | 3.2 ± 0.3c | 3.8 ± 0.4c |
| MN/18-pdmNP | 3.2 ± 0.5bc | 5.8 ± 1.1c | 3.2 ± 0.4c | 4.4 ± 0.2cd |
a
Shown are the mean (±SEM) percentages of macroscopic lung consolidation, microscopic lung and trachea composite scores, and BALF virus titers of pigs experimentally inoculated with the challenge viruses or negative control pigs. Superscript letters b, c, and d depict statistically significant differences between values in the same column (P < 0.05).