Figure 1. Intranasal challenge with N. meningitidis induces lethal disease in CD46^+/+ mice.

10⁷ CFU of N. meningitidis were administrated i.n. once per day for two days to CD46 transgenic (CD46^+/+) and non-transgenic B6C3F1 mice (Control), n = 10 per group. (A) CD46^+/+ mice showing disease symptoms were sacrificed. Nasal washes, CSF and blood samples were collected as described in Materials and Methods. The samples were diluted and spread on GC agar plates. The number of CFU was counted the following day. Data are presented as means ± SD. The horizontal lines in the boxes represent the mean of the values. N.D., not detected. (B) Survival rates of CD46^+/+ (bold dot line) and control (thin line) mice after i.n. challenge. Disease status was monitored for 10 days post-infection. The experiment was repeated three times with similar results.