TaqMan real-time RT-PCR analysis reveals that PVL does not alter agr-regulated transcripts in USA300 and USA400 clinical strains.±

±TaqMan real-time RT-PCR was performed as described in Methods. Results are expressed as the mean fold-change of 3–5 experiments (exponential growth, Exp.) or 4–7 experiments (stationary phase of growth, Stat.) with one exceptiona (one of the TaqMan reactions failed, n = 2). The relative expression level of each transcript (dCT) was compared in parent vs. Δpvl strains using a paired Student's t-test (*Ppvl). Except for lukF-PV, none of the transcripts in any of the strains met standard criteria required for differentially expressed genes (>2-fold change in the wild-type vs. Δpvl mutant strain and PagrA, accessory global regulator; hla, alpha-toxin; hlgA, gamma-haemolysin component A; splA, serine protease; spa, protein A; sdrD, serine aspartate repeat protein; clfB, clumping factor B; and lukF-PV, Panton-Valentine leukocidin component F.