Figure 6.

Reactivation Tuberculosis in the Mouse at 200 days. The Cornell model is produced by inducing latent TB in mice by treatment with antibiotics. The disease then reactivates months later as typical bronchogenic TB. It is a tuberculous lipid pneumonia quite different from the granulomas of primary murine TB. Like human post primary TB, it typically begins as sub pleural wedge shaped pneumonic lesions. Bronchial obstructions are frequently found at the apex of the wedge (arrow and insert). Acid fast bacilli are present in low numbers in alveolar macrophages. No granulomas are present in these animals. The dark purple areas are primarily interstitial lymphocytes while the pale areas they surround are alveoli filled with foamy macrophages. (H&E 100×).