Daptomycin exerts bactericidal effect through induction of excessive ROS production and blocking the function of stress response protein Usp2

Abstract Daptomycin, as a lipopeptide antibiotic, exhibits high potency in the treatment of infections caused by clinically relevant drug‐resistant Gram‐positive pathogens, such as methicillin‐resistant Staphylococcus aureus and vancomycin‐resistant Enterococci. However, its bactericidal mechanism of action remains controversial. In this study, we report that daptomycin kills bacteria through triggering overproduction of deleterious reactive oxygen species (ROS). This outcome is attributed to daptomycin binding to the universal stress response protein (Usp2) and subsequent blocking its function, triggering stress, and anti‐ROS response. Based on these findings, we conclude that daptomycin causes bacterial cell death by simultaneously triggering ROS production through inflicting cell membrane damages and inhibiting antioxidant defense by blocking Usp2 function. This study depicts molecular mechanisms underlying the bactericidal effect of daptomycin, a combination of triggering ROS production and inhibiting anti‐ROS response. Key points Novel bactericidal mechanism of daptomycin by ROS Identification of first bacterial protein target, Usp2, for daptomycin Deciphering the dual role of Usp2 on daptomycin mediated bacterial killing