| Title | Inhibitory Effects of 4-Hydroxy-2,5-Dimethyl-3(2H)-Furanone (HDMF) on Acyl-Homoserine Lactone-Mediated Virulence Factor Production and Biofilm Formation in Pseudomonas aeruginosa PAO1 |
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| Author | Sung-Chan Choi1, Can Zhang2, Sooyoung Moon2, and Young-Sook Oh2* |
| Address | 1Department of Environmental Sciences and Biotechnology, Hallym University, Chunchon 200-702, Republic of Korea, 2Department of Environmental Engineering and Energy, Myongji University, Yongin 449-728, Republic of Korea |
| Bibliography | Journal of Microbiology, 52(9),734–742, 2014, |
| DOI | 10.1007/s12275-014-4060-x |
| Key Words | acyl-homoserine lactone, biofilm, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, Pseudomonas aeruginosa, quorum sensing |
| Abstract | 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), a nonhalogenated furanone found in a variety of fruits, has been shown to have antimicrobial activity. However, few studies have focused on its inhibitory effect on bacterial quorum sensing (QS) at levels below the non-inhibitory concentration. In this study, 0.1 μM HDMF decreased the production of QS signal molecules and inhibited QS-controlled biofilm formation by Pseudomonas aeruginosa PAO1 without causing growth inhibition. In the presence of 0.1 and 1.0 μM HDMF, biofilm production by PAO1 was reduced by 27.8 and 42.6%, respectively, compared to that by untreated control cells. HDMF (1.0 μM) also significantly affected virulence factor expression (regulated by the las, rhl, and pqs system), resulting in a significant reduction in the production of LasA protease (53.8%), rhamnolipid (40.9%), and pyocyanin (51.4%). This HDMF-dependent inhibition of virulence factor expression was overcome by increasing the levels of two QS signal molecules of P. aeruginosa, N-(3-oxo-dodecanoyl)-L-homoserine lactone and N-butyryl-L-homoserine lactone, suggesting reversible competitive inhibition between HDMF and these molecules. The results of this study indicate that HDMF has great potential as an inhibitor of QS, and that it may be of value as a therapeutic agent and in biofilm control, without increasing selective pressure for resistance development. |