# Quorum-Quenching Activity of Myrtus communis Corsican Essential Oil Against the Marine Bacterium Aliivibrio fischeri

## TL;DR

This study shows that Myrtus communis essential oil disrupts bacterial communication in Aliivibrio fischeri, suggesting its potential as a natural anti-virulence agent.

## Contribution

The study identifies Myrtus communis essential oil as a novel and potent quorum-quenching agent with activity comparable to known inhibitors.

## Key findings

- Myrtus communis essential oil significantly interferes with quorum sensing traits in Aliivibrio fischeri.
- Polar fractions of the essential oil showed strong anti-quorum sensing activity, suggesting minor compounds contribute to bioactivity.
- Myrtus communis EO and its fractions exhibited stronger anti-QS effects than Origanum vulgaris EO.

## Abstract

The quorum-quenching activity of essential oils (EOs) from Corsican aromatic plants was evaluated using the marine bacterium Aliivibrio fischeri as a model system. Among the eleven EOs screened, Myrtus communis EO showed significant interference with QS-regulated phenotypes (swimming motility, bioluminescence, and biofilm formation). Its activity was compared to Origanum vulgaris EO, known for its high carvacrol content and potent QS inhibition. The fractionation of M. communis EO revealed that its most polar fractions exhibited comparable levels of QS-disrupting activity. These chromatographic fractions significantly affected QS-controlled traits, indicating that minor or less volatile compounds may contribute to, or enhance, the overall bioactivity. Furthermore, M. communis EO and its polar fractions displayed stronger anti-QS effects against A. fischeri than O. vulgaris EO. These results highlight M. communis EO as a promising source of natural QS inhibitors and underscore the importance of exploring both complete EOs and their active fractions. This study supports the valorization of Mediterranean endemic flora as a reservoir of bioactive compounds, tested on a model system A. fischeri, and encourages future research on the potential of Myrtus communis against clinical bacterial isolates and the development of novel anti-virulence strategies.