Catalyzes the NADPH-dependent reductive condensation of pyruvate to the intermediate formed by the adjacently encoded enzyme CntL, namely (2S)-2-amino-4-{[(1R)-1-carboxy-2-(1H-imidazol-4-yl)ethyl]amino}butanoate, leading to the production of staphylopine. This is the last step in the biosynthesis of the metallophore staphylopine, which is involved in the acquisition of nickel, cobalt, zinc, copper, and iron, and thus enables bacterial growth inside the host, where metal access is limited. Therefore, this enzyme probably contributes to staphylococcal virulence. Can use neither NADH nor alpha-ketoglutarate in place of NADPH and pyruvate, respectively. H2O + NADP(+) + staphylopine = (2S)-2-amino-4-{[(1R)-1-carboxy-2-(1H-imidazol-4-yl)ethyl]amino}butanoate + H(+) + NADPH + pyruvate kcat is 0.26 sec(-1) with pyruvate as substrate. kcat is 0.26 sec(-1) with oxaloacetate as substrate. kcat is 0.074 sec(-1) with glyoxylate as substrate (at pH 8.0 and 22 degrees Celsius). Homodimer. Up-regulated in metal-poor media. Belongs to the staphylopine dehydrogenase family.