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Figure 1 | BMC Microbiology

Figure 1

From: Altered cellular infiltration and cytokine levels during early Mycobacterium tuberculosis sigC mutant infection are associated with late-stage disease attenuation and milder immunopathology in mice

Figure 1

DBA/2 mouse survival score and CFU counts. The mean CFU counts were obtained from the lung homogenates of 5 mice per group and plated on 7H10 agar plates (A). ΔsigC mutant (◇), ΔsigC complemented mutant (△) and the wild type strain, CDC1551 (□), CFU counts were obtained by homogenizing individual lungs from each group and plating on 7H10 agar plates. Day 1 CFU counts were performed to confirm the dose of bacilli in each group. Mice were sacrificed for CFU counts and immunological assays on days 7, 14, 28, 70 and 120 post infections. CFU counts from ΔsigC mutant infected mice were significantly lower than in mice infected with either the CDC1551 or the complemented mutant strain (** = p < 0.01). (B) From the Kaplan-Meier survival curve, the median survival for the ΔsigC mutant infected group is more than 365 days post infection. This difference is significant with a log rank test p value of < 0.002. (C) Lungs of the three groups of DBA/2 mice infected with the ΔsigC mutant strain, the complemented ΔsigC mutant and the wild type strain, CDC1551, collected at day 120. Lung sections were stained with haematoxylin and eosin (H&E) (a-c) (Magnification ×20) and for acid fast bacilli (AFB) (d-f) (Magnification ×1000).

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