Figure 2.
Bacterial loads per organs and representative lung pathology of different vaccinated C57BL/6 mice. Three weeks after the last immunization, C57BL/6 mice (n = 6) were challenged by Glas-Col inhalation exposure system with 60 CFU virulent M. tuberculosis H37Rv strain, which was confirmed by plating lung homogenates one day after infection. Four weeks post-challenge, bacterial load of lung and spleen in different groups was enumerated. Results were shown as mean ± SEM log10CFU/organ (n = 6). Lung tissue sections from different vaccinated mice were stained by HE (scale bar, 400 μm) and acid-fast staining (AF, scale bar, 50 μm), respectively. Arrows indicate AF positive bacteria. Pathological scores were calculated as described in the section of Materials and Methods in detail. ─ means P < 0.05.