Visualization of M. tuberculosis in Animal Models Figure 5. Location of M. tuberculosis bacilli in lungs from M. tuberculosis infected guinea pigs, throughout infection and after 6 weeks of INH or TMC207 drug treatment. (AR) auramine-rhodamine, hematoxylin QS and DAPI; (H&E) hematoxylin and eosin. (A, B) Low (A) and high (B) magnifications of an early primary granuloma in the lungs of M. tuberculosis infected guinea pigs 4 weeks post-aerosol infection. Primary granulomas are distinguished from secondary lesions by the presence of necrosis (N) (H&E staining, 1006 and 10006 magnifications). (C) A secondary lesion in PLoS ONE | www.plosone.org 8 March 2011 | Volume 6 | Issue 3 | e17550