FIG 7.

Comparison of wild-type and a pneumolysin-negative mutant of strain LgSt215 in CBA/Ca mice. BALF was harvested at predetermined time points during the course of infection, and the number of viable pneumococci as well as the number of inflammatory cells and levels of selected cytokines were enumerated (n = 8), and the error bars show standard errors of the means. (A) Number of viable pneumococci in the BALF; (B) number of neutrophils; (C) number of macrophages counted in 10 fields of view at ×400 magnification. Levels of the cytokines KC (D) and IL-12 p40 (E) were measured in the BALF. Two-way analysis of variance with Sidak's multiple comparisons test was used to compare differences between the wild-type and pneumolysin-negative pneumococci: *, P values of <0.05 and >0.01; **, P values of <0.01 and >0.001; ***, P values of <0.001 and >0.0001; ****, P values of <0.0001.