Figure 4

Priming effect of Staphylococcus chromogenes IM in the murine mammary gland against Streptococcus uberis infection. Bacterial growth of A S. uberis and B S. chromogenes IM, concentrations of G IL-8 and H LCN2 in mouse mammary glands, as well as representative H&E-stained sections thereof, harvested 48 h after intraductally inoculating C, E sham (PBS) or D, F 10⁴ CFU S. chromogenes IM, followed by a second inoculation after a 24 h interval with either C, D sham or E, F 10³ CFU S. uberis NADC C-1. Data are shown as individual points with a line indicating the mean and an error bar representing the SEM. Double (**) and triple (***) asterisks indicate respectively p < 0.01 and p < 0.001, whereas “ns” indicates non-significance corresponding to a p > 0.05. Pictures were taken at a ×10 and ×40 magnification, with scale bars indicating 100 µm and 25 µm, respectively.