FIG 4.

qRT-PCR analysis of tst transcripts and relevant regulators in wild-type S. aureus MN8 and the saeS, sarA, and agr mutants. (A) cDNA was prepared at the indicated time points, and copies were normalized to the housekeeping rpoB gene. Data represent the means ± SEM from four biological replicates (*, P < 0.05, **, P < 0.01, and ***, P < 0.001, by one-way ANOVA with Tukey's multiple comparison test). (B) Exoprotein profiles (top panel) and anti-TSST-1 Western blot (bottom panel) analysis of the indicated S. aureus strains at the 4- and 8-h time points. Molecular mass markers were loaded on the left (labeled in kilodaltons), and purified recombinant TSST-1 was loaded on the right (indicated by solid arrowheads).