New strategies based on natural compounds for controlling biofilm formation

Biofilm is a complex differentiated surface-associated microbial community embedded in a self-produced polymeric matrix enabling microorganisms to develop coordinated and efficient survival strategies1. All human artefact surfaces like industrial installations, work benches, harbor systems, water distribution systems and also medical devices are all susceptible to colonization by microorganisms growing in biofilms with important consequences in term of social and economic impact2. The most detrimental property of biofilms is that conventional biocidal practices often were proved inadequate since, by adopting the sessile mode of life, microorganisms improve their resistance to antimicrobial agents up to several orders of magnitude3. In addition, increasingly restrictive regulations limiting the use of substances hazardous to human health and the environment, have resulted in several biocides being banned. In this contest the development of new improved effective solutions able to replace the presently dominating drug/device products is becoming imperative. An innovative approach would create permanently non-leaching, long-lasting bio-hybrid materials by covalent functionalization of polymeric materials with bio-inspired non-toxic and biocide-free anti-biofilm compounds. The new technology would be able to interfere with the key-steps that orchestrate device-pathogen interactions in order to hampering infection cascade. Depriving microorganisms of their ability to develop biofilm without affecting their existence may decrease selection pressure for drug-resistant mutations, restoring the efficacy of traditional antimicrobial agents. In this contest nature represents an immense source of new bioactive substances with unrivalled structural diversity and complexity. Plants and animals have adaptively developed fascinating strategies over millions of years to prevent harmful bacterial colonization on their living tissues in response to an ever-present pathogen pressure. These natural strategies were considered a promising starting point for novel anti-biofilm approaches.