Experimental design and virus load in tissues after in vivo inoculation with PRCV strains ISU-1 and 135. (A) Forty pigs were infected with 1 × 107 PFU of PRCV ISU-1 (black) or 135 (red) by the intratracheal/intranasal route. At 1, 5, 11 and 20 DPI, 5 animals per group were culled. (B) Viral load in daily nasal swabs (NS). (C) Significant differences in nasal shedding determined by the area under the curve (AUC). (D) BAL fluid, (E) trachea tissue, (F) tracheal swabs, (G) accessory lung lobe, and (H) eyelid were determined by plaque assay. Each point represents one animal with error bars defining SEM. Statistical differences at each time point were analysed using unpaired t test with Welch correction or 2-way ANOVA with a Bonferroni test for multiple comparisons. Asterisks represent significant changes (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001).
