FIG 3.
Agr activity and PSM production are low in synovial fluid. (A and B) Activity of the Agr P3 (A) and the Agr P2 promoter (B) measured during suspended growth in SF, human serum, or TSB, using genome-integrated, single-copy luxABCDE luciferase operon reporter fusion constructs. (C and D) Expression of RNAIII (C) and agrA (D) at 8 h of growth, measured by qRT-PCR. (E and F) Expression of psmα (E) and psmβ (F) promoters during growth in SF, human serum, or TSB, using genome-integrated, single-copy luxABCDE luciferase operon reporter fusion constructs. (G) Expression of psmα operon by qRT-PCR, at 8 h of growth. (H) PSM production determined in culture filtrates after 8 h of growth. All experiments were performed in triplicate. Error bars show standard deviations (SD). *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.