Analogues of Pseudomonas aeruginosa signalling molecules to tackle infections.

The emergence of antibiotic resistance coupled with the lack of investment by pharmaceutical companies necessitates a new look at how we tackle bacterial infections. An intriguing tactic is the interruption of bacterial communication systems. This non-biocidal approach would circumvent the evolutionary pressure on bacteria to mutate and develop resistance. In many pathogenic microorganisms, communication systems, collectively termed quorum sensing (QS), have been observed to control a number of bacterial behaviours including expression of virulence factors and the development of biofilms. QS signalling molecules and their biomimetics, therefore, represent a rational target for the disruption of cooperative behaviour and thus the development of novel antimicrobial strategies. Herein we review recent developments towards the interference of Pseudomonas aeruginosa QS using signalling molecules and their mimetics.

Exploiting Interkingdom Interactions for Development of Small-Molecule Inhibitors of Candida albicans Biofilm Formation.

A rapid decline in the development of new antimicrobial therapeutics has coincided with the emergence of new and more aggressive multidrug-resistant pathogens. Pathogens are protected from antibiotic activity by their ability to enter an aggregative biofilm state. Therefore, disrupting this process in pathogens is a key strategy for the development of next-generation antimicrobials. Here, we present a suite of compounds, based on the Pseudomonas aeruginosa 2-heptyl-4(1H)-quinolone (HHQ) core quinolone interkingdom signal structure, that exhibit noncytotoxic antibiofilm activity toward the fungal pathogen Candida albicans In addition to providing new insights into what is a clinically important bacterium-fungus interaction, the capacity to modularize the functionality of the quinolone signals is an important advance in harnessing the therapeutic potential of signaling molecules in general. This provides a platform for the development of potent next-generation small-molecule therapeutics targeting clinically relevant fungal pathogens.