Quorum sensing signal interference within and across the kingdoms

Abstract

Quorum sensing (QS) is known to be widespread in prokaryotic world for regulating numerous important biological activities. Consequently, anti-QS approaches have recently been proposed as a promising strategy for development of novel antimicrobial agents by uncoupling bacterial QS. In this study, I explored further on the QS signal interference within and across the kingdoms. The microbial diversity in multi-species biofilms was inspected and both QS signal producing and degrading bacterial species were identified. A putative QS inhibitor (PAi), isolated from Pseudomonas aeruginosa has been purified and characterized as 2-amino-4-methoxy-but-3-enoic acid. The molecular mechanisms of PAi production were also investigated. A novel enzymic anti-QS mechanism was identified from eukaryotic kingdom. Further analysis revealed that mammalian sera possess a widely conserved catalytic mechanism different from bacterial AHL-lactonase, although they share a similar function in degrading QS signals.