Photoinactivation of Catalase Sensitizes Wide-Ranging Bacteria to ROS-Producing Agents and Immune Cells

AbstractBacteria have evolved to cope with the detrimental effects of reactive oxygen species (ROS) using their essential molecular components. Catalase, a heme-containing tetramer protein expressed universally in most of the aerobic bacteria, plays an indispensable role in scavenging excess hydrogen peroxide (H2O2). Here, through utilization of wild-type and catalase-deficient mutants, we identified catalase as an endogenous therapeutic target of 400-420 nm blue light. Catalase residing in bacteria could be effectively inactivated by blue light, subsequently rendering the pathogens extremely vulnerable to H2O2 and H2O2-producing agents. As a result, photoinactivation of catalase and H2O2 synergistically eliminate a wide range of catalase-positive planktonic bacteria and P. aeruginosa inside biofilms. In addition, photoinactivation of catalase is shown to facilitate macrophages to defend against intracellular pathogens. The antimicrobial efficacy of catalase photoinactivation is further validated using a Pseudomonas aeruginosa-induced mice abrasion model. Taken together, our findings offer a catalase-targeting phototherapy against multidrug-resistant bacterial infections.