Bioluminescent Imaging of Implant Infections

As previously described [46 (link)–49 (link)], the IVIS Lumina X5 (PerkinElmer, Waltham, MA) was used to obtain bioluminescent images representative of infectious burden on postoperative days (POD) 0, 1, 3, 5, 7, 10, 14, 18, 21, 25 and 28. Data were quantified as total flux (photons per second per cm² per steradian [photons/s/cm²/sr]). Mice were sacrificed on POD 28 and bacterial CFU counts of the bacteria adherent to the implant as well as in the surrounding joint tissue were quantified. To isolate adherent bacteria, implants underwent sonication in 500 μL 0.3% Tween-80 (ThermoFisher Scientific) in TSB. To isolate bacteria in the surrounding joint tissue, tissue was homogenized in 1000 μL of PBS with 4 homogenizing beads (Pro200H Series homogenizer; Pro Scientific) and the implants underwent sonication in 500 μL 0.3% Tween-80 (ThermoFisher Scientific) in TSB. Samples from tissue and implants were then drop plated and incubated for 16 hours at 37°C. CFUs were counted and expressed as CFUs/mL.