(A) Intracellular ATP levels. Comparison of S. aureus LAC wild-type (WT, BS819) and Δagr mutant (BS1348) strains for ATP expressed as µg/108 cells after growth of cultures in Tryptic Soy Broth (TSB) medium to late-exponential phase (OD600~4.0). (B) Extracellular acetate levels. Samples were taken after 1, 2, 3, 4, and 24 hr of growth in TSB medium; strains were wild-type (WT, BS819) and Δagr mutant (BS1348). (C–D) Extracellular lactate and acetate levels during low oxygen culture. S. aureus LAC wild-type (WT, BS819) and Δagr mutant (BS1348) were grown in TSB medium with suboptimal aeration to late-exponential phase (4 hr, OD600~4.0). (E–F) Oxygen consumption. Strains LAC wild-type (WT, BS819) and Δagr mutant (BS1348) were compared using Seahorse XFp analyzer (F), and the rate of oxygen consumption (E) was determined from the linear portion of the consumption curve. Representative experiments from at least three independent assays are shown. (G–H) NAD+ and NADH levels. Colorimetric assay of NAD+ (G) and NADH levels (H) for S. aureus wild-type (WT, BS819) and Δagr mutant (BS1348) after growth of cultures to late-exponential phase (OD600~4.0). (I) NAD+/NADH ratio. For all panels, data points are the mean value ± SD (n=3). *p<0.05; ****p<0.0001, by Student’s two-tailed t-test. Seahorse statistical significances are compared to TSB medium.