Objectives: Staphylococcus aureus, a Gram-positive bacteria, is ranked second among the
causes of hospital infections and is one of the three main causes of food poisoning. In recent times, the
spread of antibiotic resistance in S. aureus has become very worrisome. Therefore, research for new
effective drugs is important. The present study aims to investigate the phytochemical profiles and antibacterial
effects of hydroalcoholic extracts of Origanum vulgare (Lamiaceae family) and Hypericum
perforatum (Clusiaceae family) and their active compounds on S. aureus (ATCC 12600) in vitro.
Methods: The identification of phytochemical compounds in both plants was performed by Highperformance
liquid chromatography (HPLC), headspace-solid-phase microextraction (HS-SPME) and
Fourier-transform infrared spectroscopy (FTIR). To investigate microbial susceptibility, minimum inhibitory
concentration (MIC), minimum bactericidal concentration (MBC) and disc diffusion method
(DAD) were used. Finally, the results of the study were compared with methicillin.
Results: Of the 42 combinations of O. vulgare, carvacrol (48%) and of the 38 combinations of H. perforatum,
hypericin (46.2%) were the most abundant. The MIC, MBC and DAD of O. vulgare and H.
perforatum, carvacrol, hypericin and methicillin were 625, 625, 312.5, 78.12 and 384 μg/mL, 10000,
10000, 2500, 2500 and 384 μg/mL, and 15.66 ± 4.49, 12.66 ± 0.47 and 22 ± 0.81 mm, respectively.
Conclusions: Due to the significant effects of O. vulgare and H. perforatum and their active components
against S. aureus, it is expected that in the future, hypericin, carvacrol and their derivatives can
be used as effective antibacterial agents against S. aureus.