Inhibition of Pseudomonas aeruginosa and Escherichia coli O157:H7 Biofilm Formation by Plant Metabolite ε‑Viniferin

Abstract

Pathogenic biofilms are associated with persistent infection due to their high resistances to diverse antibiotics. Pseudomonas aeruginosa infects plants, animals, and humans and is a major cause of nosocomial diseases in patients with cystic fibrosis. In the present study, the antibiofilm abilities of 522 plant extracts against <i>P. aeruginosa</i> PA14 were examined. Three <i>Carex</i> plant extracts at a concentration of 200 μg/mL inhibited <i>P. aeruginosa</i> biofilm formation by >80% without affecting planktonic cell growth. In the most active extract of Carex pumila, resveratrol dimer ε-viniferin was one of the main antibiofilm compounds against <i>P. aeruginosa</i>. Interestingly, ε-viniferin at 10 μg/mL inhibited biofilm formation of enterohemorrhagic Escherichia coli O157:H7 by 98%. Although <i>Carex</i> extracts and <i>trans</i>-resveratrol are known to possess antimicrobial activity, this study is the first to report that <i>C. pumila</i> extract and ε-viniferin have antibiofilm activity against <i>P. aeruginosa</i> and <i>E. coli</i> O157:H7