Fig. 4
A S. aureus purR mutant is hypervirulent via FnbAB. In a, mice (9–12 per group) were infected with ~1 × 107 CFU of WT USA300, USA300 purR::ΦNΣ or complemented purR::ΦNΣ mutant and survival monitored over 72 h. ***p-value < 0.001, based on a Mantel-Cox test. In b, animals were infected as in a, but with 2–2.5 × 106 CFU, and c weight loss monitored daily for 48 h. **p-value < 0.01, ***p-value < 0.001, based on a one-way ANOVA with a Bonferroni post-test. In d, animals from b were sacrificed at 48 h post infection (hpi), and heart, kidney and liver were harvested and bacterial burdens determined. Data shown are mean ± SEM, *p-value < 0.05, **p-value < 0.01, ***p-value < 0.001, based on a Student’s unpaired t-test. In e, two animals per bacterial strain were infected as in a, with ~1 × 107 CFU, sacrificed at 24 hpi and organs harvested. Organs were paraffin embedded, sectioned and stained with H&E and a Gram stain. Representative images are shown. In f, animals were infected as in a, with ~1 × 107 CFU, with the inclusion of WTΔfnbAB and purR::ΦNΣΔfnbAB strains, and monitored for 72 h. ***p-value < 0.001, based on a Mantel-Cox test. In g, the heart, kidney and liver from the animals infected in e were harvested at the point of sacrifice and bacterial burden determined. Data shown are mean ± SEM, *p-value < 0.05, **p-value < 0.01, ***p-value < 0.001, based on a Student’s unpaired t-test. Source data are provided as a Source Data file
