In vitro Susceptibility of Some Bacteria Strains to Ethanol Extracts of Propolis Collected from Two Different Geographic Origins in Cameroon

摘要

Antibacterial activity of fifteen samples of Ethanol Extracts of Propolis (EEP) prepared from propolis collected in two different geographic regions of Cameroon were investigated. Those antibacterial properties were determined by the well diffusion method on agar medium and by evaluating the Minimal Inhibitory Concentration (MIC) according to the macrodilution method. The activities of EEP were tested against seven strains of bacteria including four gram positive strains and three gram negative strains. All the samples of EEP studied were active only against gram positive bacteria. The most active samples were the EEP1 and EEP12 (p<0.05). Considering the MIC values, the most susceptible strains to the most active EEP tested were Listeria monocytogenes, Staphylococcus aureus and Bacillus subtilis with a MIC≤18.60 μg mL-1, the least susceptible strain was Enterococcus faecalis to the EEP11 with a MIC value equal to 36.20 μg mL-1. Considering the Principal Component Analysis (PCA), the areas of the minor and the major peaks of the phenolic compounds obtained by HPLC showed a relationship with antibacterial activities of the EEP. The EEP antibacterial properties were also linked to their geographic origins.