Mice infected with Mtb-HT strains show presence of solid discrete granulomas.

H&E stained sections of formalin-fixed paraffin-embedded tissues from the lungs of Mtb-HT infected C3HeB/FeJ mice obtained at 12 weeks post infection show well defined tubercle granuloma (square box) (A). Higher magnifications zoomed-in images show presence of peribronchiolar lymphocytes (B) and open alveolar spaces with less inflamed alveolar septae (C). AFB staining (D). High magnification images were taken using a Leica DM6000B by objective imaging at 20X and 100X and also by analyzing high-magnification scanned images using Aperio ImageScope. These images are representative of pathology seen with all three Mtb-HT infections.