Fig. 5

Time course infection of C3HeB/FeJ mice infected with MAC101. Lung (A), spleen (B) and liver (C) bacterial burden (y-axis, log₁₀ CFU) in C3HeB/FeJ mice infected by intrapulmonary aerosol with high (10⁵ CFU) and low (10³ CFU) dose of MAC101 was measured 4-weekly for 12 weeks. Histological lesion scoring of lungs was performed at weeks 4, 8 and 12 (D), calculated as the proportion of infected area over the total lung area per animal (n = 3–4 per group). Inflammatory changes were mild, as demonstrated in representative histological heat maps at week 12 post-infection (E + F). Higher magnification revealed small aggregates of macrophages and epithelioid cells (G, H&E staining) with scattered intracellular bacteria (H, red arrows, Ziehl-Neeson staining). Data is representative of two studies (n = 3–8 per time point) and displayed as mean ± SD (A-C) or as individual data points with median line (D). Differences between time points were analysed by unpaired t-test (A-C) or by one-way ANOVA with Turkey’s multiple comparison test (D)