IN VITRO ANTIBACTERIAL EVALUATION OF CATHARANTHUS ROSEUS (L.) G.DON LEAF EXTRACT ON SOME VEGETATIVE BACTERIA

摘要

An in vitro evaluation of the antibacterial activity of aqueous and ethanolic leaf extract of Catharanthus roseus (L.) G. Don (= Vinca rosea Linn.) on some vegetative bacteria was carried out. The agar well diffusion method was used to determine the sensitivity pattern of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. A varied degree of inhibition was observed at different concentrations of the extract. The zone of inhibition produced by the ethanolic leaf extract ranged from 15.0mm to 19.8mm while that of aqueous leaf extract ranged from 11.0mm - 17.6mm. Results showed that S. aureus displayed the highest susceptibility in the ethanolic leaf extract (16.4mm-19.8mm) followed by E. coli (15.0mm - 18.3mm) and least susceptibilitywas observed in P. aeruginosa (15.2mm - 17.8mm). In the aqueous leaf extract, P. aeruginosa gave the highest susceptibility (15.0mm-l7.6mm), followed by E. coli (14.4mm-16.0mm) and the least susceptible was S. aureus (11.0mm -14.8mm). The results revealed that both the aqueous and ethanolic leaf extract were effective in inhibiting the growth of the bacteria.