Widespread Existence of Quorum Sensing Inhibitors in Marine Bacteria: Potential Drugs to Combat Pathogens with Novel Strategies

Abstract

Quorum sensing (QS) is a phenomenon of intercellular communication discovered mainly in bacteria. A QS system consisting of QS signal molecules and regulatory protein components could control physiological behaviors and virulence gene expression of bacterial pathogens. Therefore, QS inhibition could be a novel strategy to combat pathogens and related diseases. QS inhibitors (QSIs), mainly categorized into small chemical molecules and quorum quenching enzymes, could be extracted from diverse sources in marine environment and terrestrial environment. With the focus on the exploitation of marine resources in recent years, more and more QSIs from the marine environment have been investigated. In this article, we present a comprehensive review of QSIs from marine bacteria. Firstly, screening work of marine bacteria with potential QSIs was concluded and these marine bacteria were classified. Afterwards, two categories of marine bacteria-derived QSIs were summarized from the aspects of sources, structures, QS inhibition mechanisms, environmental tolerance, effects/applications, etc. Next, structural modification of natural small molecule QSIs for future drug development was discussed. Finally, potential applications of QSIs from marine bacteria in human healthcare, aquaculture, crop cultivation, etc. were elucidated, indicating promising and extensive application perspectives of QS disruption as a novel antimicrobial strategy.

Keywords: QS inhibition mechanisms; QS inhibitors; application; marine bacteria; quorum quenching enzymes; small molecule QS inhibitors; structural modification.

Figure 1

Large-scale prescreening showed abundance of marine bacteria with potential quorum sensing (QS) inhibition activities.

Figure 2

Classification and relative abundance of the marine bacteria isolates with potential QS inhibition activities. The genera represented by a single isolate are grouped as “other”.

Figure 3

Structure modification of natural marine bacteria-derived QSIs/chemical compounds to obtain more potent QSIs. To the left of the arrow are natural QSIs or natural chemical compounds without QS-inhibitory activity. To the right of the arrow are novel QSIs after structure modification.