FIG. 5.

Increases in numbers of lung CFU following i.t. inoculation of B. anthracis occurs coincident with colonization of the spleen. Mice were inoculated i.t. with ∼5,000 spores of B. anthracis. The data represent two separate experiments. Mice (five per group) were euthanized at 5, 20, and 40 h postinoculation, and the numbers of CFU in the lung and the spleen were determined. In experiment 2, only two mice were alive at the 40-h time point. The upper graphs show numbers of lung CFU at the three time points, and the lower graphs show numbers of splenic CFU. Each lane in the upper graphs represents a single mouse, and the lower bars show the corresponding splenic CFU.