Anti-Biofilm Activity of Viruses, Bacteria, Fungi, and Lichens: Mechanisms and Impact on Clinical Practice

Abstract

When adopting a sessile lifestyle, bacteria gain the adaptive ability to tolerate a wide range of antimicrobials, becoming increasingly resilient. In the clinic, there is an acute need to find new options for the treatment of biofilm-driven infections, and research on biofilm-active agents is well underway. In this chapter, we aim to characterize the existing body of knowledge on the topic of natural anti-biofilm compounds, by describing the main types of agents, their mechanisms and their potential clinical role and impact on medical practice. Bacteriophages are viruses that infect bacterial cells and either destroy the cells or circumvent their ability to form biofilms, through the action of specific enzymes. Bacteria can also synthetize specific molecules, bioactive peptides, or secondary metabolites that display anti-biofilm activity either through a lytic action or through inhibiting the formation of extracellular polymeric substances. Last but not least, anti-biofilm compounds have also been isolated from clinically relevant fungi or lichen-associated fungi, as some of their cell wall components or secondary metabolites may display important roles in limiting bacterial and fungal biofilms alike.