FIG 6.

S. aureus strains exhibit distinct levels of Agr activity, as assessed by VLT and RNAIII gene expression. (A) The bacterial supernatant was incubated with lipid vesicles at a 1:1 ratio, and the fluorescence intensity was recorded as a measure of vesicle lysis. (B) RNAIII activity was measured by using quantitative RT-PCR, as a ratio of RNAIII to gyrB transcript numbers. Results are expressed as means ± standard errors of the means (n = 3 to 4). *, P < 0.05; **, P < 0.01; ***, P < 0.001 (as determined by one-way ANOVA with a Tukey posttest).