Antibacterial properties studies of trunk barks of terminalia ivorensis (Combretaceae), a commercial and medicinal specie, on some methicillin-resistant Staphylococci spp strains

Background: Methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis and coagulase-negative Staphylococcus infections are a worldwide concern. Terminalia ivorensis, of Combretaceae family plant, is widely used traditional medicinal in Côte d’Ivoire to treat dermal diseases (affection in which Staphylococci are implied) including local inflammation and also to treat voice-loss. Objectives: This study focused to investigate the effect in vitro of the extracts of trunk barks of Terminalia ivorensis on some methicillin/oxacillin-resistant strains of Staphylococcus aureus, S. epidermidis, coagulase-negative S. and reference strain of S. aureus ATCC 25923. Methods: Antibacterial activity of aqueous, 70% ethanolic 70% and aqueous residue extracts was assessed using agar disc-diffusion method and liquid medium microdilution method in 96 multi-well micro-titer plates. This method led us to determine minimum inhibition concentration (M.I.C.) and minimum bactericidal concentration (M.B.C.). The presence of chemical groups major was detected qualitatively. Results: Aqueous and 70% ethanolic 70% extracts showed significant activity against all the bacteria except aqueous residue when compared with the standard antibiotic oxacillin (5μg/ml). M.I.C. for aqueous and 70% ethanolic 70% extracts ranged from 0,83-16,67 mg/ml and 0,156-13,33 mg/ml respectively. Viable cell determination revealed the bactericidal nature of the two barks extracts. The 70% ethanolic 70% extract exhibited the highest activity according to the M.B.C. values. The phytochemical analysis indicates the presence of tannins, saponins, flavonoids, terpen/sterols, coumarins, polyphenols and traces of alkaloid. Conclusion: The in-vitro antibacterial efficacy shown by the barks of this plant and his lushness in chimical compounds, would justify use of this one in the traditional treatment of some diseases of microbial origin. These compounds could be suggested to provide alternative solution to the development of new therapeutic agents.