Propolis is a natural resin collected and modified by honeybees. Since ancient times it has been used as a chemotherapeutic agent. The propolis antibacterial activity was evaluated through bacterial inoculation on BHI agar plates with 5% of alcoholic propolis extract (10(6) bacteria. mL-1). One hundred and sixty one bacterial strains were evaluated, as Gram positive bacteria (Staphylococcus sp., Streptococcus sp., Nocardia asteroides and Rhodococcus equi) as Gram negative (Escherichia coli, Salmonella sp., Proteus mirabilis and Pseudomonas aeruginosa). The strain was considered sensible to the propolis extract when no bacterial growth was evident on the plate after 72 hours at 37ºC. The control test used agar plates with 5% of ethanol (M2) and 5% of saline solution. Propolis extract demonstrated antibacterial activity on 67.7% of the tested strains; 92.6% of Gram-positive and 42.5% of Gram-negative strains presented sensitivity. The propolis extract showed effective antibacterial activity against the majority of tested strains.
flavonoids; antibacterial activity; sensitivity
