Fig 7.
Meningococcal ΔpilT and ΔpilU mutants are less virulent than the wild type in a mouse model of meningococcal disease. Human CD46 transgenic mice were infected i.p. with the wild-type strain, the ΔpilT mutant, or the ΔpilU mutant (108 CFU/mouse). (A) Bacterial counts in blood (CFU/ml) were determined 2, 6, 24, and 48 h after the start of infection. Statistically significant values are indicated with asterisks (P < 0.05; Kruskal-Wallis nonparametric one-way ANOVA). (B) Survival of mice (n = 7 to 9 mice per group) after i.p. challenge with the wild-type strain, the ΔpilT mutant, or the ΔpilU mutant (*, P < 0.05; Kaplan-Meier survival analysis).