Antimicrobial effect of Hydroxytyrosol, Hydroxytyrosol Acetate and Hydroxytyrosol Oleate on Staphylococcus Aureus and Staphylococcus Epidermidis

Introduction: Increasing microbial resistance to antibiotics is one of the main contributors for replacing the appropriate compounds to treat microbial infections. Staphylococcus is one of the most important genera of the bacteria as some strains present on the skin as normal flora and opportunistic infectious agents. Common resistance to antibiotics has been observed in infections caused by this genus from bacteria. Plants have different chemical compounds with antimicrobial properties. The aim of this study was to evaluate the effect of antimicrobial activity of hydroxytyrosol, hydroxytyrosol acetate and hydroxytyrosol oleate which are derived from the leaves of the olive on S. epidermidis and S. aureus. Methods: Hydroxytyrosol, hydroxytyrosol acetate and hydroxytyrosol oleate that are two lipophilic derivatives of hydroxytyrosol, which have been prepared at Magna Graecia University, Italy. The antibiogram test was carried out according to the CLSI guidelines and the Kirby-Bauer method using well assay and Microplate broth dilution for S. aureus and S. epidermidis. Results: The highest Zone of inhibition for the HT, HTA and HTO compounds for Staphylococcus aureus was 30, 19 and 15 mm at a concentration of 100 mg/ml respectively. The highest Zone of inhibition for the HT, HTA and HTO compounds for Staphylococcus epidermidis was 25, 19 and 14 mm at a concentration of 100 mg/ml respectively. The MIC for the above compounds for Staphylococcus aureus was 3.125, 12.5 and 25 mg/ml respectively. The MIC for the above compounds for Staphylococcus epidermidis was 6.25, 12.5 and 50 mg/ml respectively. Conclusion: Respectively, the highest antimicrobial activity against S. aureus and S. epidermidis was evaluated in hydroxytyrosol, hydroxytyrosol acetate and hydroxytyrosol oleate compounds.