Fig. 1

In vivo noninvasive monitoring of bacterial dissemination and burden in older and younger mice HOIAI. Three weeks after sterile surgical placement of an orthopaedic K-wire in the right distal femurs of older and younger mice (n = 19–21 mice/group), a bioluminescent MRSA strain was inoculated intravenously and in vivo BLI signals for the operative (op) and contralateral non-operative (non-op) legs were measured along with body weights for 28 days. a Representative in vivo BLI imaging (log scale). b Mean maximum flux (photons/s/cm²/sr) ± s.e.m. LOD = level of detection (3.3 × 10³ photons/s/cm²/sr). c Euler diagram depicting the number of mice with and/or without detectable in vivo BLI signals above the LOD in the op, non-op or both op and non-op legs. d Mean body weight (grams) ± s.e.m. *P < 0.05, †P < 0.01, and ‡P < 0.001, between op versus non-op for older and younger groups of mice, as calculated by 2-way ANOVA across all time points (b), 2-tailed Fischer’s exact test (c) or 2-tailed Mann-Whitney U test (d). n.s. not significant