AUTHOR=Li Wen-Ru , Zeng Tao-Hua , Zhang Zhi-Qing , Shi Qing-Shan , Xie Xiao-Bao 

TITLE=Geraniol attenuates virulence factors by inhibiting quorum sensing of Pseudomonas aeruginosa

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1190619

DOI=10.3389/fmicb.2023.1190619

ISSN=1664-302X

ABSTRACT=<p><italic>Pseudomonas aeruginosa</italic> is a ubiquitous opportunistic pathogen that can cause severe respiratory tract infections. Geraniol, a chemical component of essential oils, has antimicrobial and anti-inflammatory activities, along with low toxicity. However, the effect and mechanism of geraniol against <italic>P. aeruginosa</italic> virulence factors are rarely studied. In this study, we investigated the quorum sensing (QS) inhibitory effects and mechanisms of geraniol against <italic>P. aeruginosa</italic> PAO1, using physiological and biochemical techniques, quantitative reverse transcription polymerase chain reaction, and transcriptomics. Geraniol slightly affected <italic>P. aeruginosa</italic> PAO1 growth, prolonged the lag phase, and delayed growth periods in a concentration-dependent manner. Geraniol inhibited three QS systems of <italic>P. aeruginosa</italic>, <italic>las</italic>, <italic>rhl</italic>, and <italic>pqs</italic> by suppressing the expression level of their key genes, including the three signal synthetase encoding genes of <italic>lasI</italic>, <italic>rhlI</italic>, and <italic>pqsABCDEH</italic>, and the corresponding signal receptor encoding genes of <italic>lasR</italic>, <italic>rhlR</italic>, and <italic>pqsR</italic>. Geraniol also suppressed certain virulence genes regulated by these three QS systems, including <italic>rhlABC</italic>, <italic>lasAB</italic>, <italic>lecAB</italic>, <italic>phzABMS</italic>, and <italic>pelABG</italic>, resulting in the attenuation of the related virulence factors, rhamnolipids, exoprotease LasA, elastase, lectin, pyocyanin, and biofilm. In conclusion, geraniol can suppress the virulence factors of <italic>P. aeruginosa</italic> PAO1 by inhibiting the three QS systems of <italic>las</italic>, <italic>rhl</italic>, and <italic>pqs</italic>. This study is significant for improving the treatment of bacterial infections caused by <italic>P. aeruginosa</italic>.</p>