Antibacterial activity of propolis against Staphylococcus aureus

Depending on concentration, collecting area, and time, EEP exerted various degrees of antibacterial activity against S. aureus. The minimum inhibitory concentration of EEP tested ranged from <3.75 to 60 μg/ml, while the minimum bactericidal concentration ranged between 7.5 and 120 μg/ml against S. aureus. In general, a higher antibacterial activity was noted with EEP collected in August than other months. EEP of Mingchien-6 showed the most profound antibacterial activity among the EEP samples tested. The age of a bacterial culture affected its susceptibility to EEP. Cells in the late-exponential phase were most susceptible to EEP. Higher temperature (37 °C) and acidic pH enhanced the antibacterial activity of EEP.