Vancomycin-based tracers guiding in situ visualization of bacteria on osteosynthesis devices and surgical debridement.

Abstract

Bacterial infections associated with musculoskeletal injuries are challenging to detect and distinguish from sterile inflammation. Here we present the combined first-time application of a bacteria-targeted positron emission tomography (PET) tracer and a near-infrared fluorescent tracer to detect infected osteosynthesis implants and guide surgical treatment. To this end, osteosynthesis plates covered with bacterial biofilm and pre-incubated with [¹⁸F]PQ-VE1-vancomycin for PET imaging and/or vancomycin-IRDye800CW for optical imaging were fixed to post-mortem human tibiae and femora. PET/CT and fluorescence imaging were used to quantify the bacterial load before and after surgical debridement. Pre-debridement, PET imaging showed a significant 2.2-fold higher tracer uptake on biofilm-covered plates compared to plates without biofilm (p < 0.001). Post-debridement, the PET signal was marginal, demonstrating effective biofilm removal. Fluorescence-guided surgery enabled real-time visualization and removal of bacterial biofilms. Combined preoperative PET and intraoperative fluorescence imaging with vancomycin-based tracers allows noninvasive detection and real-time infection management, as demonstrated by these preliminary findings.