Our aim is to develop a new way of modulating microbial behaviour, relying on how these microorganisms respond to synthetic polymers. Most “antimicrobial” polymers will either try to induce microbial death, normally compromising membrane integrity, or inhibit the adhesion to host or surfaces. However, bacteria will respond and adapt to the presence of these polymers often triggering downstream cellular signalling , to affect phenotypical changes such as biofilm production or virulence factor expression.
Alternatively, we have recently reported how cationic polymers can be used to activate off-target phenotypes in bacteria. Bacteria, normally negatively charged, are clustered in the presence of non-toxic concentrations of positively charged polymers. Then, bacteria respond to this clustering by activating downstream processes such as inducing light production in luminescent bacteria, or inhibiting virulence in the human pathogen Vibrio cholerae. We believe that our results suggest that we can control what phenotypes are activated and switched off in bacteria, if the right combination of chemical (e.g. charge, hydrophobicity) and physical (e.g. attachment, clustering) cues are integrated in the polymer design. We believe this type of materials will underpin the development of novel “antimicrobial” polymers or adjuvants, or the future development of biofilms for biotechnology.
- Engineering microbial physiology with synthetic polymers: cationic polymers induce biofilm formation in Vibrio cholerae and downregulate the expression of virulence genes. Chem. Sci. 8, 5291–5298 (2017).
- Bacteria clustering by polymers induces the expression of quorum-sensing-controlled phenotypes. Nat. Chem. 5, 1058–1065 (2013).