FIG. 4.
Effect of mutations in pspC and pspA in a mouse bacteremia model. Groups of five mice (BALB/cByJ) were challenged intravenously with 1 × 106 CFU of wild-type pneumococci (D39), pspA-negative D39 (JY53), pspC-negative D39 (TRE108), and pspA- and pspC-negative D39 (TRE121). The presence of bacteria in the blood was determined at 1 min, 1 h, and 4 h (a). Subsequently, the number of hours to death was determined in each case (b). P values versus the wild type were calculated by using the Wilcoxon two-sample rank test. Mice that did not die after 21 days (504 h) were assigned a time to death of 504 h for statistical purposes. In each graph, values that are significantly different from D39 are indicated by asterisks.