Bacterial activity of crude extracts of Vernonia amygdalina on clinical isolates

The antibacterial activities and preliminary phytochemical screening of ethanolic and aqeous extract of Vernonia amygdalina was performed against clinical isolates obtained from University of Ilorin Teaching Hospital (UITH) which included Escherichia coil, Staphylococcus aureus andPseudomonas aeruginosa. Generally, the ethanol extracts showed more activities than aqueous extracts in both samples. The extracts exhibited antibacterial activity against the test organisms (0.5 to 15.50 mm). The phytochemical screening of Vernonia amydalina showed the presence of tannins, cardiac glycosides, saponins and alkaloids. The minimum inhibitory concentration (MIC) ranged between 25 and 200 mg/ml. V. amydalina exhibited a minimum bacteriocidal concentration (MBC) of 50 mg/ml for P. aeruginosa and 125 mg/ml for S. aureuswhile E. coil was bacteriostastic. The crude extracts exhibited strong potency against the clinical bacteria with P. aeruginosa being the most susceptible. The antibacterial efficacy of the crude extracts is therefore discussed.   Key words: Antimicrobial activity, minimum inhibitory concentration, phytochemical, Vernonia amygdalina