Investigation of antibacterial activities of Albizia gummifera and Ferula communis on Streptococcus pneumoniae and Streptoccus pyogenes.

BACKGROUND: Respiratory Tract infections continue to be a major cause of morbidity and mortality world wide. There is a failure to treat respiratory infections due to the emergence of antibiotic resistant strains among the most common respiratory pathogens.

OBJECTIVES: To evaluate the in vitro antibacterial activities of two traditionally used plants: Albizia gummifera (Ambabesa-Muka, Oromifa, Sessa-Amharic.) and Ferula communis (Doge-Oromifa, Dog-Amharic) against clinical isolates of S. pyogenes and S. pneumoniae.

METHODS: The study involving the antibacterial susceptibility test of traditionally used plant species against Gram-positive bacterial pathogens was conducted over a period of 5 months (January - August, 2004) at the Ethiopian Health, and Nutrition Research Institute. The in vitro antibacterial activities of 80% methanol crude extracts prepared from the seeds of Ablizia gummifera and, roots of Ferula communis as well as their respective hydro alcoholic solvent fractionates of both plant species were tested for inhibitory activity against the clinical isolates of six S. pneumonae and twenty two S. pyogenes using agar dilution method.

RESULTS: Eighty percent ethanol solubilized fractions of both plants were found to have antibacterial effects to all assayed bacteria while aqueous solubilized fractions did not exhibit any effect. Minimum inhibitory concentration (MIC) of the 80% ethanol solubilized fractions was determined and the MIC of the fractions ranged from 500 mg/ ml to 1000 mg/ml for both plants showing the extracts may contain bioactive compounds of therapeutic interest.

CONCLUSION: All extracts showed antibacterial activities against clinical isolates of S. pyogenes and S. pneumoniae. The extracts may contain compounds with potential therapeutic activity. Further purification and identification are needed to be tested using animal models.