Quorum Sensing Antagonism from Marine Organisms

Abstract

With the global emergence of multiresistant bacteria there is an increasing demand for development of new treatments to combat pathogens. Bacterial cell-cell communication [quorum sensing (QS)] regulates expression of virulence factors in a number of bacterial pathogens and is a new promising target for the control of infectious bacteria. We present the results of screening of 284 extracts of marine organisms from the Great Barrier Reef, Australia, for their inhibition of QS. Of the 284 extracts, 64 (23%) were active in a general, LuxR-derived QS screen, and of these 36 (56%) were also active in a specific Pseudomonas aeruginosa QS screen. Extracts of the marine sponge Luffariella variabilis proved active in both systems. The secondary metabolites manoalide, manoalide monoacetate, and secomanoalide isolated from the sponge showed strong QS inhibition of a lasB::gfp(ASV) fusion, demonstrating the potential for further identification of specific QS antagonists from marine organisms.

Exploiting Quorum Sensing To Confuse Bacterial Pathogens

“…Aquatic ecosystems continue to reveal diverse microorganism taxonomies and to yield enormous diversity in secondary metabolite products. Numerous reports are emerging that provide empirical data demonstrating QSI activity from various marine sources that include sponges (290), microalgae (291), bryozoa (292), and alga-and coral-associated bacteria (293,294). Low-micromolar concentrations of phenethylamide compounds from the marine bacterium Halobacillus salinus were found to inhibit V. harveyi luminescence and C. violaceum pigment production without inhibiting growth (295).…”

“…Low-micromolar concentrations of phenethylamide compounds from the marine bacterium Halobacillus salinus were found to inhibit V. harveyi luminescence and C. violaceum pigment production without inhibiting growth (295). Secondary metabolites isolated and purified from sponges (290) and Gram-negative cyanobacteria (296) also exemplify successes where low-micromolar concentrations of purified compounds could inhibit QS reporters. Recently, for example, low-molecularweight compounds isolated from the marine cyanobacterium Leptolyngbya and named honaucins A to C (for Honaunau Bay, HI, the location of the reef where the bacteria were isolated) (Table 3) exhibited potent, low-micromolar QSI activity in both a V. harveyi bioluminescence assay and an E. coli AHL reporter assay (140).…”

Signaling-mediated cross-talk modulates swarming and biofilm formation in a coral pathogen Serratia marcescens

“…Production of QS signals has also been reported in cultures of coral-associated vibrios, although the role of QS in coral diseases caused by these microorganisms has not yet been established (Tait et al, 2010). Because QS has important roles in the interactions within microbial communities, various forms of QS manipulation have been documented (Givskov et al, 1996;Pasmore and Costerton, 2003;Skindersoe et al, 2008;Dobretsov et al, 2009). How these interactions carry out in natural habitats is far from being clear.…”

Antibiofilm activity substances derived from coral symbiotic bacterial extract inhibit biofouling by the model strainPseudomonas aeruginosaPAO1

“…The marine environment is a rich storehouse of natural products possessing antibiofilm properties, and accumulating evidence has confirmed the existence of a diverse array of active compounds in coral, bryozoans, sponge and pyrosomida (Skindersoe et al ., 2008; Tello et al ., 2012). Furthermore, studies increasingly point to types of planktonic marine bacteria, such as Bacillus spp., Pseudomonas spp., Pseudoalteromonsa spp., and Vibrio spp., as frequent sources for the production of QSI compounds (Teasdale et al ., 2009; Mangwani et al ., 2015; Benneche et al ., 2016; Casillo et al ., 2017).…”