Bacterial Quorum Sensing is a cell-to-cell communication process, in which, bacteria, performing cooperative behaviour, produce and detect extracellular signalling chemicals, to monitor cell population density. Numerous bacterial processes including bioluminescence, virulence factor production, biofilm formation etc. are known to be influenced by this bacterial communication network.
A systematic study was performed with twelve different cyclodextrin compounds (natural CDs, HP, RAME, QA and polymer derivatives) in order to determine their concentration- and time-dependent bioluminescence inhibitory effect in the Aliivibrio fischeri model system, using the bacterium which produces light based on quorum sensing. Especially high quorum quenching effect was found for α-cyclodextrin: 10 mM α-cyclodextrin at 120 min contact time which caused ~64% inhibition of bioluminescence. Experiments with the co-administration of α-cyclodextrin and N-(3-oxohexanoyl)-L-homoserine lactone, the signalling molecule of A. fischeri clearly showed, that the stimulating effect of this signal was diminished by α-cyclodextrin, suggesting, that complexation was responsible for the observed Quorum Sensing suppression.
Although β-cyclodextrin and its hydroxypropyl derivative significantly inhibited bioluminescence at as low as 0.156 mM concentration, their efficiency did not reach the level of α-cyclodextrin.
Mónika Molnár, Éva Fenyvesi, Zsófia Berkl, Imre Németh, IldikóFekete-Kertész, Rita Márton, Emese Vaszita, Erzsébet Varga, Dóra Ujj, Lajos Szente (2021) Cyclodextrin-mediated quorum quenching in the Aliivibrio fischeri bioluminescence model system – Modulation of bacterial communication.
International Journal of Pharmaceutics 594, 120150. https://doi.org/10.1016/j.ijpharm.2020.120150
The source of featured image: https://www.nature.com/articles/s41592-019-0311-4