In vitro antibacterial activity of Baillonella toxisperma (Pierre) extracts against Staphylococcus aureus, Salmonella typhi, Proteus mirabilis and Bacillus cereus F3748

This study evaluated the in vitro antibacterial activity of the ethyl acetate, acetone, methanol and hydro-ethanol mixture (2: 8) extracts of the leaves and stem-barks of Baillonella toxisperma (Pierre), harvested in the East and center regions of Cameroon, on Staphylococcus aureus, Salmonella typhi, Proteus mirabilis and Bacillus cereus F3748. These bacteria are usually responsible for diarrheal diseases and in severe cases can lead to the dead of patients. The susceptibility of the bacteria to the extracts was evaluated by the well diffusion method and the inhibition parameters of the bacterial growth were determined by the micro-dilution assay according to the directives of document M27-A9 (2012) of the Clinical and Laboratory Standards Institutes (CLSI). The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal concentrations (MBC) obtained were between 1.56 and 25.00 mg/ml. Stem-barks ethyl acetate extract from the East region, was most active on S. aureus, S. typhi and P. mirabilis with a MBC of 6.25 mg/ml. The leaves methanolic extracts from the center region was the most active with a MBC of 6.25 mg/ml on S. aureus. The ratio MBC/MIC shows that the majority of the extracts were bacteriostatic on the strains tested. The phytochimical screening revealed that the plant contained bioactive substances such as phenols, tannins, flavonoids, steroids, alkaloids, saponins, triterpenes and cardiac glycosides, reported by several authors for their antibacterial activity. The results obtained validate the traditional use of this plant in the treatment of affections of bacterial origin.