Antibacterial activity of water and acetone extracts of the roots of Euclea natalensis.

Water and acetone extracts of the roots of Euclea natalensis A.DC. were investigated for their in vitro antibacterial properties. The Gram-positive bacteria tested appeared to be more susceptible to the extracts than the Gram-negative bacteria. The water and acetone extracts inhibited the growth of Bacillus cereus, Bacillus pumilus, Bacillus subtilis, Micrococcus kristinae and Staphylococcus aureus at concentrations ranging between 0.1 and 6.0 mg/ml. The water extract did not exert any inhibitory action on Gram-negative bacteria while the acetone extract showed inhibitory activity at a concentration of 5.0 mg/ml against all the Gram-negative bacteria investigated. The antibacterial activity of acetone extract was also investigated by a direct bioassay on TLC plates against S. aureus.