Antibacterial activity of syrian propolis extract against several strains of bacteria in vitro

We aimed in this study to evaluate the effectiveness of Syrian propolis on some bacterial strains isolated from Al-Assad hospital in Latakia, to estimate its antimicrobial activity. Thus, we studied two propolis samples from two regions in the Syrian coast, and prepared ethanolic extracts of propolis (EEP) with different concentrations (0.5%, 1%, 5%, 10%, and 20%). Then we tested these extracts on four strains of bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii), using pore method on Muller Hinton Agar. As we observed, the bacteria showed diverse susceptibility to the extracts and the most susceptible bacterium was Staphylococcus aureus which was sensitive to all concentrations and especially for EEP 20%. However, the least affected bacteria were E. coli and Pseudomonas, as the 0.5% and 1% EEP had no efficacy. On the other hand, there were little differences in antimicrobial activity between the two samples of propolis.