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

Abstract

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