FIG 3.

Western immunoblot analysis of PVL (LukF) production in S. aureus strains TS12 (agr group 3), TS13 (agr group I), and TS14 (agr group 1) in response to exogenous AIP. (a) PVL production in the absence of AIP (TS12, TS13, and TS14) or after the addition of AIP-1 (TS13) or AIP-3 (TS12) at the time of inoculation (time zero [0 h]; TS12 and TS13) or after 6 h (TS13); for TS14, (Ala⁵)AIP-1 was also added at 0 h. (b) LukF production profiles over time for TS13 and TS14. (c) PVL production profile over time after exogenous addition of AIP-1 to TS13 at 0 h or after 5.5 h. (d) PVL production by TS14 after 24 h is reduced when (Ala⁵)AIP-1 is added at 0 h or after 2 h but not after 4 or 6 h.