Fig. 3.

Effect of panchvalkal formulation on S. aureus (*p < 0.05, **p < 0.01, ***p < 0.001; AS: Antibiotic susceptibility; QS: Quorum sensing; PF: Panchvalkal formulation) 3(A). Effect of PF on growth and QS regulated staphyloxanthin production in S. aureus: Bacterial growth was measured as OD₇₆₄; OD of staphyloxanthin was measured at 450 nm, and staphyloxanthin unit was calculated as the ratio OD₄₅₀/OD₇₆₄ (an indication of staphyloxanthin production per unit of growth); ‘Control’ bar in this figure is the ‘vehicle control’ representing the % change values in comparison to the ‘growth control’ i.e. tube containing only growth medium plus organism, but no DMSO. 3(B). Kaplan–Meier survival curve showing the protective effect of PF on C. elegans, when challenged with S. aureus: Catechin (50 μg/ml) and Gentamicin (0.1 μg/ml) employed as positive controls conferred 100% and 80% protection respectively. DMSO present in the ‘vehicle control’ at 0.5%v/v did not affect virulence of the bacterium towards C. elegans. 3(C). Effect of PF on S. aureus growth remained unaltered even after repeated exposure to PF, but that on staphyloxanthin was reversed. 3(D). S. aureus challenged with PF and antibiotic together. 3(E). S. aureus challenged with antibiotic following pre-treatment with PF (250 μg/ml).