Figure 3

Relative gene expression in nasal samples after S. suis intranasal inoculation. Log₂ of the individual values and mean (black bars) of the relative gene expression in nasal samples in S. suis inoculated piglets (gene expression was normalized relative to the 3 days before challenge mean for each inoculated group). Piglets were intranasally inoculated with S. suis T15 (non-virulent, blue bars) or S10 (virulent, red bars) strains, and nasal swabs were taken at 4 h and 1, 2 and 3 days after inoculation. Genes showing significant difference (P < 0.05) in pairwise analysis when comparing different time points in the S. suis inoculated groups or between strains at the same time point, and with a mean greater than 2-fold change (log₂ = 1) are shown. * P < 0.05 when comparing versus their respective 3 days before challenge time point. n = 8 for both strains at 4 h post-infection and 1 dpi, n = 4 for both strains at 2 and 3 dpi. IL1B 1 and IL1B 2 are both IL1B assays consisting of two different primer pairs targeting non-overlapping sites in the IL1B transcript. All expression values and significant differences can be found in Additional file 3.