NAD kinase controls antibiotic susceptibility and pathogenic potential in Staphylococcus aureus

Abstract

AbstractNicotinamide adenine dinucleotide phosphate (NADPH) is the primary electron donor for reductive reactions that are essential for the biosynthesis of major cell components in all organisms. Nicotinamide adenine dinucleotide kinase (NADK) is the only enzyme that catalyzes synthesis of NADP(H) from NAD(H). While the enzymatic properties and physiological functions of NADK have been thoroughly studied, the role of NADK in bacterial pathogenesis remains unknown. Here, we used CRISPR interference to knockdown NADK gene expression in order to address the role of NADK in Staphylococcus aureus pathogenic potential. We find that NADK protects bacteria from antimicrobial defense mechanisms encountered in the host during infection such as oxidative and envelope stresses. Furthermore, we show that antioxidant properties of NADK promote S. aureus survival in infected macrophages. Remarkably, NADK inhibition drastically decreases mortality of zebrafish infected with S. aureus. These findings support a key role for NADK in bacteria interactions with innate immune cells and during infection. Last, we reveal that decreasing NADK expression increases S. aureus susceptibility to antibiotics, opening the way to development of synergistic treatments based on NADK inhibitors and current antibiotics.