Fig. 2.

Effect of panchvalkal formulation on S. marcescens (*p < 0.05, **p < 0.01, ***p < 0.001; AS: Antibiotic susceptibility; QS: Quorum sensing; PF: Panchvalkal formulation) 2 (A)Effect of PF on growth and QS regulated prodigiosin production in S. marcescens: Bacterial growth was measured as OD₇₆₄; OD of prodigiosin was measured at 535 nm, and prodigiosin unit was calculated as the ratio OD₅₃₅/OD₇₆₄ (an indication of prodigiosin 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. 2 (B). Kaplan–Meier survival curve showing the protective effect of PF (250 μg/ml) on C. elegans, when challenged with S. marcescens: Catechin (50 μg/ml) and Ofloxacin (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. 2 (C). S. marcescens challenged with PF and antibiotic together. 2 (D). S. marcescens challenged with antibiotic following pre-treatment with PF (250 μg/ml).