Antibacterial Effect And Clinical Potential Of Honey Collected From Scaptotrigona Bipunctata Lepeletier (1836) And Africanized Bees Apis Mellifera Latreille And Their Mixture

Bacterial resistance to conventional antibacterial agents is a clinical issue which requires the constant search for new therapies. This study evaluated the antibacterial activity of honey produced by Scaptotrigona bipunctata (HSB) and Africanized bees Apis mellifera (HAM) against Gram-negative and Gram-positive bacterial strains. Six assays were performed to analyze the antibacterial effects: 1) Agar well-diffusion assay (AWD), 2) Microdilution assay, 3) Checkerboard assay, 4) Time-kill curve, 5) Scanning electron microscopy (SEM), and 6) Oxygen superoxide production assay. Treatments with HSB alone and the HSB/HAM combination showed inhibition zones against all strains analyzed in the AWD assay. Minimal inhibitory concentration (MIC) of HAM ranged from 20 to 25% (vv(-1)) in all microdilution assays, while MIC of HSB ranged from 1.25 to 5% (vv(-1)). HSB showed a bactericidal effect against Staphylococcus aureus and a hindering effect on Escherichia coli growth, while HAM demonstrated bacteriostatic activity against both strains. The mixture of both honeys demonstrated an additive effect in their antibacterial activities, reducing the MIC value of each honey. This same mixture induced higher oxygen superoxide production, when compared with isolated honeys. HSB and HAM samples, when treated with catalase, presented an increased MIC value against S. aureus and E. coli, however. the mixture demonstrated antibacterial synergic effect under the same treatment. Blebs and furrows on the surface of S. aureus were observed by electronic microscopy after bacterial exposure to HSB and HAM, respectively. These results indicate different antibacterial mechanisms of the honeys, and the mixture of them presented multiple effects on bacterial strains, suggesting the application of these honeys as an alternative for the control of bacterial infections.