Quorum quenching and biofilm-degrading activity of massoia oil against Candida albicans and Pseudomonas aeruginosa

Abstract

Targeting the quorum sensing system and interrupting microbial communication, is an example of an anti-pathogenic effect and may provide a solution to increasing antibiotic resistance. Fungi use quorum sensing to affect population-level behaviours, such as biofilm formation and pathogenesis [1]. Previous anti-infective studies on Indonesian medicinal plants have focused mainly on anti-microbial drug discovery perspectives. However, no systemic effort has been made to explore the anti-quorum sensing (quorum quenching) activity of these plants. The aim of this study is to evaluate quorum quenching activity of Massoia aromatica essential oil using a quorum sensing violacein biosensor, Chromobacterium violaceum CV026, and biofilm eradication activity against Candida albicans ATCC10231 and Pseudomonas aeruginosa PAO1. Effectiveness of Massoia oil to inhibit the swarming motility of P. aeruginosa PAO1 are of interest, since microbial biofilm and motility have been shown to be associated with microbial virulence [2,3]. Massoia oil was obtained by steam distillation process. Microtiter plate method was used to test for the biofilm eradication activity. Effect of Massoia oil on microbial biofilms architecture was assessed using Confocal Laser Scanning Microscopy (CLSM) along with LIVE/DEAD staining. Standard disc diffusion assay was used to detect quorum quenching activity. Our study revealed that violacein production in the reporter strain was impeded by Massoia oil. Disruption of established microbial biofilms, and significant reduction in quorum sensing related motility of P. aeruginosa PAO1 by Massoia oil were also observed.