Fig. 5.

The growth of Δndh and ΔndhΔnuoAN is attenuated in immunocompetent mice infected via the aerosol route. C57BL/6 mice were infected with CDC1551 (black circles), Δndh (red squares), and ΔndhΔnuoAN (purple triangles) via a low-dose (∼100 bacilli) aerosol. Lungs (A) and spleens (B and D) were collected, homogenized, and plated to determine organ bacterial burden at 1, 3, and 8 wk postinfection. cfu counts in lungs and spleen are shown for each individual mouse, and geometric mean is indicated for each group. The limit of detection is indicated by a dotted line. (C) Lung tissue sections at 8 wk postinfection were stained with hematoxylin/eosin and observed at a magnification of 2.5×.