The antimicrobial action of Pseudomonas aeruginosa byproducts in the control of single and mixed biofilms

Abstract

Since bacteria are continuously acquiring resistance to conventional chemical agents, it is urgently needed the development of new strategies for biofilm control. It is well recognised that certain microorganisms represent an important source of novel biologically active compounds, with pronounced antibacterial activity, as secondary metabolites. Such substances are accepted to be essential for their producers, inhibiting other bacteria that compete for common resources. The main goal of this work was to investigate the antimicrobial effect of secondary metabolites secreted by P. aeruginosa on planktonic and sessile growth of several pathogens, in order to later use those molecules as bio-regulation agents. P. aeruginosa supernatants had potential as anti-biofilm agents but only against staphylococcal biofilms since they failed in disturb other biofilm consortia that encompassed Grambacteria. This trait makes them quite ineffective chemical countermeasures against real biofilms.