EN
Studies on the antibacterial action of 592 samples of propolis from various regions of Poland showed that ethanolic extracts of propolis differ by their antibacterial activity. The minimal inhibitory concentration (MIC) of the extracts ranged from 60 to 490 µg/ml and the minimal bactericidal concentration (MBC) ranged from 110 to 1680 µg/ml for Staphylococcus aureus 209P (Oxford). Samples of propolis of a determined bacteriostatic activity differ clearly by the MBC values. Therefore, standardization of propolis should be based both on the MIC and MBC values. Authors suggest that the most active propolis should characterize the MIC below 300 µg/ml and the MBC not more than 450 µg/ml. The methods of extraction and antibacterial activity determination have to be strictly defined because they affect both the MIC and MBC of propolis.