Antimicrobial Agent Evaluation Using Planktonic, Biofilm-Forming and Preformed Biofilm Cell States

摘要

The characterization of antimicrobial efficacy in three different stages of bacterial growth, including the often overlooked evaluation of preformed biofilms, provides a more comprehensive examination of antimicrobials and further sheds light on potential mechanisms of action. QPS-1 had similar effective concentrations in planktonic cultures and biofilm formation studies, suggesting that its mechanism of action occurs before biofilm formation. However, the small increase (＜ 10-fold) needed for full antimicrobial activity in preformed biofilms further indicates that the mechanism of action is not as affected in biofilms as compared to antibiotics, which typically require 100 to 1000 fold higher concentrations for anti-biofilm properties. Due to its promising anti-biofilm activities at low concentrations, QPS-1 is a candidate molecule to impart antimicrobial activity to biomaterials.