Fig. 1

The effect of Zn and Cu stress on A. baumannii growth and metal ion homeostasis. Growth as determined by measuring the optical density at 600 nm (OD₆₀₀) of A. baumannii strain ATCC 17978 under increasing concentrations of (a) Zn, (b) Cu, or (c) Zn + Cu (n ≥ 3). Examination of the (d) Zn, (e) Cu and (f) Fe levels in untreated cells and cells grown in the presence of 400 μM Zn, 400 μM Cu or 400 μM Zn + 400 μM Cu. The cellular metal ion content (in microgram) per gram of desiccated cells was determined by ICP-MS. The data are the mean of at least biological triplicates (± SEM). Statistical analyses were performed using a two-tailed Student’s t-test; ns = not significant and * = p < 0.05