COMPOSITION, ANTIBIOFILM, AND ANTIBACTERIAL POTENTIAL OF VOLATILE OILS FROM GEOPROPOLIS OF DIFFERENT STINGLESS BEES’ SPECIES

The propolis volatile oils (VO) have aroused interest due to their biological activities, including the antimicrobial one. Geopropolis samples were collected from Melipona bicolor schencki, M. compressipes manaosensis, M. fasciculata, M. quadrifasciata, M. marginata and M. seminigra merrillae hives in Santa Catarina (SC, Brazil). In vitro minimal inhibitory concentration (MIC) essays were performed against mycoplasmas and cell-walled bacteria of standard strains and isolated from clinical specimens. The VOs that presented the lowest MIC against Mycoplasma pneumoniae FH (MP) were submitted to fractionation and VO samples with the lowest MIC were tested regarding its antibiofilm activity. The lowest MIC against cell walled bacteria was 219±0 µg mL-1 from M. quadrifasciata geopropolis VO against Staphylococcus aureus. The M. b. schencki geopropolis VO MIC was 424±0 µg mL-1 against all the mycoplasmas strains tested. Fractionation resulted in the reduction of 50% of the MIC value from the original oil. Antibiofilm assays demonstrated 15.25% eradication activity and 13.20% inhibition of biofilm formation after 24h for one subfraction at 2x its MIC as the best results found. This may be one of the essential mechanisms by which geopropolis VOs perform their antimicrobial activity.