The Effect of Subinhibitory Concentrations of trans-Anethole on Antibacterial and Antibiofilm Activity of Mupirocin Against Mupirocin-Resistant Staphylococcus aureus Strains

Aim: The aim of this study was to evaluate the effect of subinhibitory concentrations of trans-anethole on antibacterial and antibiofilm properties of mupirocin against mupirocin-resistant Staphylococcus aureus strains. Methods: Following parameters were examined: isolates susceptibility to antibiotics, minimum inhibitory concentration (MIC) of trans-anethole, antibacterial activity of mupirocin/trans-anethole combination, detection of ileS2 gene, genotypic relativity of isolates using pulsed-field gel electrophoresis method, and the influence of mupirocin/trans-anethole combination on S. aureus biofilm formation. Results: Our study revealed that trans-anethole combined with mupirocin increased the growth inhibition zone diameter around the mupirocin disk, independently on S. aureus strains susceptibility to this antibiotic. Moreover, combination of subinhibitory (MIC50) concentration of mupirocin and trans-anethole significantly decreased biofilm biomass. Conclusions: trans-Anethole appeared efficient in increasing susceptibility to mupirocin and decreasing biofilm formation in S. aureus strains used in this study. Reduction of biofilm formation can potentially protect against S. aureus recolonization. Moreover, use of trans-anethole in combination with mupirocin can increase the mupirocin activity against methicillin-resistant and mupirocin-resistant S. aureus strains.