Figure 4

HO-1^−/− mice showed diffuse M. avium infection in lung issue as opposed to HO-1^+/+ mice that contained the mycobacteria in mature, well-formed granulomas. The lung sections were stained with fluorescent auramine stain (BD Biosciences, Sparks, MD, USA) to show M. avium (green color) in lung tissue. (a) Auramine stain of HO-1^+/+ control lung. (b) Auramine stain of HO-1^+/+ lung infected with M. avium for 6 months. (c) Auramine stain of HO-1^−/− lung after 6 months M. avium infection. White arrows show the presence of M. avium. (d–f) H&E stain corresponding to panels (a–c).