FIG. 4.

Global analysis of exoproteins secreted by the S. aureus wild-type strain (WT) and an isogenic strain lacking fur (Δfur). The differences in abundance of exoproteins produced by the S. aureus wild-type and isogenic strains lacking fur were determined by liquid chromatography-MS/MS and spectral counting. Exoprotein profiles were subdivided into profiles for iron acquisition (A), cytotoxins and hemolysins (B), and immunomodulatory proteins (C). The data are the means and standard errors of the means for three independent samples. The statistical significance of differences between the samples was analyzed by Student's t test (*, P < 0.05).