Synergistic interaction of extracts of garlic (Allium sativum) and propolis against methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a public health problem, being a cause of severe diseases in hospitals and communities in general. To confront this contingency at present, the effectiveness, in combination with diverse natural products is being studied in order to inhibit this microorganism. The objective of the present work was to evaluate the combined inhibitory effects of ethanolic extracts of garlic (Allium sativum) and propolis (Propolis –ppl-) against MRSA strains. We tested two types of extracts: at 20 and 30% for each. Microbial resistance assays were evaluated by the macrodilution method and the combinations were assessed by isobolographic studies. The study strains were divided into two groups based on their resistance to garlic as sensitive (36.8 ± 7.4 mg/mL) and resistant (67.2 ± 8.9 mg/mL). The results show that for strains catalogued as sensitive, the combinations in both concentrations suggest a synergistic effect; on the other hand, for strains catalogued as resistant, the combinations no longer presented a synergic effect.