Prevention, removal and inactivation of Escherichia coli and Staphylococcus aureus biofilms using selected monoterpenes of essential oils

Aims The aim of this study was to investigate the antibiofilm potential of five essential oil (EO) components with cyclic (sabinene—SAB, carveol—C1, carvone—C2) and acyclic (citronellol—C3 and citronellal—C4) structures against Escherichia coli and Staphylococcus aureus. Methods and Results The selected EO components prevented biofilm set‐up, with C3 and C4 causing remarkable effects. When applied against pre‐established biofilms, they promoted high biomass removal and inactivation of biofilm cells. Moreover, no viable E. coli biofilm cells were detected after exposure to SAB at 5 × MIC and 10 × MIC, and a significant viability decrease was observed for both bacteria with the other EO components. SAB, C3 and C4 caused the most prominent effects apparently due to their octanol–water partition coefficient (Po/w), the number of rotatable bonds (n‐ROTB) and the free hydroxyl groups. Conclusions The overall results demonstrated that the selected EO components, particularly SAB, C3 and C4 are of interest as new lead molecules to both prevent biofilm set‐up and to control pre‐established biofilms of E. coli and S. aureus. Significance and Impact of the Study The tested EO components exhibited prominent antibiofilm properties against E. coli and S. aureus providing a novel and effective alternative/complementary approach to counteract chronic infections and the transmission of diseases in clinical settings.