Background and Aim: Side effects associated with antimicrobial drugs, as well as their high cost, have stimulated the search for inexpensive herbal medicinals with fewer side effects. These substances can be used as a medicinal supplement or to increase the antimicrobial and antifungal effects of drugs. The aim of this study is to investigate the inhibitory effect of oleuropein on fungal and bacterial pathogens isolated from nail infection in laboratory condition.
 

Methods: Antifungal and antibacterial properties of oleuropein by determining the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC) of this substance on yeasts Candida albicans, Candida glabrata and Escherichia coli by microbroth dilution method using CLSI protocols were evaluated.
 

Results: The results showed that the Minimum Inhibitory Concentration (MIC) against all three studied microorganisms was equal to 65 mg/ml and the Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC) of oleuropein was equal to 130 mg/ml.
 

Conclusion: due to the high antifungal and antibacterial activity of oleuropein, the present study introduces oleuropein as a natural antimicrobial drug. This substance can also be used to increase the antimicrobial power of existing antibiotics.