Electron microscopic and microcalorimetric investigations of the possible mechanism of the antibacterial action of a defined propolis provenance.

Microcalorimetric and electron microscopic studies on the mode of the antibacterial action of propolis were performed on Streptococcus agalactiae. It was shown that propolis inhibits bacterial growth by preventing cell division, thus resulting in the formation of pseudo-multicellular streptococci. In addition, propolis disorganized the cytoplasm, the cytoplasmic membrane, and the cell wall, caused a partial bacteriolysis, and inhibited protein synthesis. It was evident that the mechanism of action of propolis on bacterial cells is complex and a simple analogy cannot be made to the mode of action of any classic antibiotics.