Thymol Reduces agr-Mediated Virulence Factor Phenol-Soluble Modulin Production in Staphylococcus aureus

Figure 7

Schematic of the S. aureus agr quorum-sensing system. The binding affinity of thymol with AgrC could affect the conformational properties of AgrC essential for dephosphorylation of ATP to ADP + Pi, leading to interference with AgrA activation. Thymol may also block the transcription function of AgrA, leading to inhibition of PSM production. Red arrows show inhibition of PSMs including δ-toxin production in S. aureus. The agents targeting agr-mediated virulence of S. aureus are shown: solonamide B, and fengycin (competitively interferes with AIP binding to AgrC) [44, 68, 69], savirin (inhibit AgrC and AgrA downstream of AIP sensing) [52], ω-hydroxyemodin (directly binds to AgrA and prevents the interaction of AgrA with P2 promoter) [70].