Figure 5.

Plate bioassays demonstrate that Staphylococcus lugdunensis HtsABC and SirABC are required for uptake of staphyloferrin A and staphyloferrin B, respectively. Water and ferric citrate were used as negative and positive controls, respectively. Supernatant extracts supplied were those of Staphylococcus aureus mutants that secrete SA (sbn mutant), SB (sfa mutant) or neither SA or SB (sfa sbn mutant). All data points represent average values for at least three independent biological replicates, and error bars represent standard deviation from the mean.