Fig. 2
Quantitative real-time bacterial burden on cortical allograft compared to stainless steel disc or cancellous allograft in a mouse model. a, b Measurement of bacterial burden using in vivo bioluminescence. S. aureus possessing the bioluminescent construct in a stable plasmid (Xen36) in the inoculum 1 × 102 CFU or no bacteria as a control were inoculated into the dorsal cervical subcutaneous space of mice in the presence of either a cortical allograft implant vs stainless steel disc (a), or cortical allograft implant vs cancellous allograft implant (b). Bacterial counts as measured by in vivo S. aureus bioluminescence [total flux (photons per s per cm2)sem (logarithmic scale)]. Error bars represent standard error of the mean. Full experimental data including 1 × 103 CFU inoculum in Supplementary Figs. 3 and 4. †P < 0.05 compared to sterile in the mixed effects regression model using a group-by-time interaction term. c Confirmation of bacterial burden using CFU counts. At POD 56 mice were sacrificed, implants were sonicated, tissue was homogenized, and bacteria was cultured and counted. Black circles represent mean. Error bars represent standard error of the mean. Gray plot points represent individual data points, and size of plot point circle is proportional to number of data points at that value. The number of bacterial CFU that were adherent to the implant and in the surrounding tissue was determined by counting CFU after overnight culture of plates, and was expressed as CFUs per mL harvested
