Piper betle leaf extract affects the quorum sensing and hence virulence of Pseudomonas aeruginosa PAO1

Abstract

Quorum sensing (QS) plays an important role in virulence of Pseudomonas aeruginosa, blocking of QS ability are viewed as viable antimicrobial chemotherapy and which may prove to be a safe anti-virulent drug. Bioactive components from Piper betle have been reported to possess antimicrobial ability. This study envisages on the anti-QS properties of ethanolic extract of P. betle leaf (PbLE) using P. aeruginosa PAO1 as a model organism. A marked reduction in swarming, swimming, and twitching ability of the bacteria is demonstrated in presence of PbLE. The biofilm and pyocyanin production also shows a marked reduction in presence of PbLE, though it does not affect the bacterial growth. Thus, the studies hint on the possible effect of the bioactive components of PbLE on reducing the virulent ability of the bacteria; identification of bioactive compounds should be investigated further.

Keywords: Anti Quorum Sensing properties; Biofilm production; Mobility pattern; Piper betle leaf extract; Pseudomonas aeruginosa; Pyocyanin assay.

Fig. 1

Effect of piper betle ethanolic leaf extract (PbLE) on the mobility pattern of Pseudomonas aeruginosa PAO1. a Effect of swarming activity, b swimming activity and c twitching activity of Pseudomonas aeruginosa PAO1 with increasing concentrations (25, 50, 75 and 100 μg/ml) of PbLE (inset showing the colony morphology of the bacteria)

Fig. 2

Inhibition of Pseudomonas aeruginosa PAO1 biofilm and pyocyanin production in presence of different concentrations of PbLE. Bar chart represents the mean results from triplet cultures of three independent experiments, with error bar representing standard deviation

Fig. 3

Growth curve patterns of Pseudomonas aeruginosa PAO1 in presence of different concentrations of PbLE (0, 50, 100 and 150 μg/ml)