Figure 10. Virulence of the Δlgt mutant strain.

(A) CIs for the Δlgt strain versus the wild-type strain in mouse models of septicaemia at 24 hours (IP inoculation, bacteria recovered from the spleen) and pneumonia at 48 hours (IN inoculation, bacteria recovered from the lungs). Each point represents the CI for a single animal. (B) Time course of the development of fatal infection for groups of 10 mice inoculated IP with 3×10³ CFU of the wild-type (WT) and Δlgt strains (P<0.0001, log rank test). (C) Log₁₀ bacterial CFU per ml of nasal wash recovered 1, 2, 5 and 10 days after nasopharyngeal colonisation of mice with 5×10⁶ CFU of the wild-type (black columns) and Δlgt D39 (clear columns) strains. P values were calculated using Mann Whitney U tests for each time point.