In vivo bioluminescence imaging of natural bacteria via ATP-binding cassette sugar transporter

Abstract The existing bioluminescence imaging (BLI) methods only visualize the location of engineered bacteria in vivo, hardly imaging natural bacteria. Herein, we leverage bacteria-specific ATP-binding cassette (ABC) sugar transporters to internalize luciferase and luciferin by hitchhiking them on the unique carbon source of bacteria, i.e., glucose polymers. Compared with bacteria with mutations in ABC sugar transporters, which hardly internalize the constructed BLI probes (i.e., ~ 2% of uptake rate), both Gram-positive bacteria and Gram-negative bacteria could robustly engulf the constructed BLI probes with a high uptake rate of around 50%. Impressively, the developed strategy enables ex vivo bioluminescence imaging of human vitreous containing ten kinds of pathogens collected from patients with bacterial endophthalmitis. By using this platform, we further differentiate bacterial and non-bacterial nephritis and colitis in mice, while their chemiluminescence counterparts (e.g., luminol) are unable to distinguish them. The proposed BLI strategy in non-transgenic bacteria without lysing bacteria expands the pool of bioluminescence applications in the microbial diagnostics within the host organism.