Figure 2.

Delayed neutrophil infiltration to the lung and impaired bacterial clearance in mice infected with Y. pestis strains 25 dpii. Mice were i.n. infected with a dose of 0.2 LD₅₀ of Kim53 (black) or with a similar dose of Kim53 administered 25 dpii (blue). Representative FACS plots (A) and a summary of neutrophil percentage in the lungs (B) of naïve or 25 dpii mice at the indicated time points after infection with Kim53 (n = 6–8 mice). (C) Bacterial loads in the lungs and spleens of naïve or influenza convalescent mice at 72 h after i.n. infection with Kim53 (n = 11–19 mice per group). (D) Neutrophil percentage in the lungs of naïve mice or 25 dpii at the indicated time points after infection with a mut-Kim53 (n = 4–11 mice). (E) Bacterial loads in the lungs (I) and spleens (II) of naïve mice infected i.n. with a mut-Kim53 strain (black) or with a similar dose administered at 25 dpii (blue). (n = 4–13 mice per group). Dotted lines denote the detection cut-off of 10 cfu per organ. #p < 0.05, ###p < 0.001 vs. Kim53 at t = 0. *p < 0.05, **p < 0.01, ***p < 0.001 vs mut-Kim53 at the same time point.