Figure 2.

Histopathology of spleen at 16 h p.i. C57BL/6 mice were infected for 16 h as in the experiments of Figure 1, and spleens were fixed in formalin and stained with hematoxylin and eosin. Representative sections are shown. Left panel, spleen from a mouse infected with parent Y. pestis; Right panels, spleen from a mouse infected with ΔyopM-1 Y. pestis. In each panel the surround indicates an inflammatory focus at the edge of a lymphoid follicle.