FIG. 5.

Effect of immunization on spleen colonization after intranasal challenge with 16M (experiments D and E). Mice were immunized intraperitoneally with WR201 (striped bars) or sham immunized with saline (stippled bars). Nine weeks later, all animals were challenged with 10⁴ 16M. Spleens were harvested at the indicated time points, and number of CFU was determined in disrupted tissue by serial dilution and plating. Each bar indicates CFU from an individual mouse. Limit of detection was 2 CFU/spleen.