Introduction:

The excessive use of antibiotics has increased pathogenic microorganisms resistance, which derives in patient mortality. Therefore, the strategies for searching new natural and unconventional strategies has become constant and important.

Objective:

To determine the antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) against stingless bees propolis.

Methods:

We evaluated nine (20 %) propolis from stingless bees ethanolic extracts from different regions: Melipona beecheii, Melipona solani, Tetragonisca angustula and Scaptotrigona mexicana. The chemical characterization was performed by liquid chromatography (HPLC) and microbial resistance tests by the macrodilution method, to determine the effect of the combinations.

Results:

The compounds that were of interests and the most abundant were the following; hydroxycinnamic acids, flavanones, flavonoids and the glycosylated derivatives. Four of the nine propolis were effective against MRSA, which came from the following species; one from M. solani and three from S. mexicana. The minimum inhibitory concentration for S. mexicana was in the range of 3-8 mg mL-1 and for M. solani it was 4 mg mL-1. Isobolographic studies resulted in an additive effect (ɤ = 1) for the combination of Allium sativum with the S. mexicana propolis sambles and an antagonistic effect (ɤ > 1) for the combination of A. sativum with the propolis of M. solani.

Conclusions:

the combination of extracts with lower concentrations of A. sativum, may be the most effective, than those that were individually tested. More detailed studies are required to define the mechanisms of stingless bees propolis as well as their combination with other organic substances.