Studies on antimicrobial effects of chromolaenaodorata on pathogenic bacteria isolates

Abstract

The study was conducted to investigate the antimicrobial effects of Chromolaenaodorata leaf on some pathogenic bacteria isolates that infect humans. The bacteria isolates include: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Proteus species. The disc diffusion method was employed to determine the inhibitory effects of the leaf extract on the tests organisms. Aqueous and ethanol extract of the leaf were used at concentration of 80g/250ml and also diluted at concentration of 1:10, 1:100, 1:1000 and 1:10000. They were impregnated into a sterile filter paper disc. Ethanol alone was also impregnated into the sterile filter paper disc and used as control. The zones of inhibition for ethanol extract (80g/250ml) of the leaf on the selected clinical isolates showed zones of inhibition of 15mm for Staphylococcus aureus, 12mm for Escherichia coli, 15mm for Pseudomonas aeruginosa and 15mm for Proteus Specie. The Zone of inhibition obtained for diluted ethanol extract (80g/250ml) of the leaf at 1:10 showed Staphylococcus aureus 12mm, Escherichia coli 11mm Pseudomonas aeruginosa 12mm and Proteus Spp. 8mm. With Ethanol alone the inhibition rate varied form 0.4mm – 0.8mm, and an out rightly resistant at 1:1000 and 1:10000 with only 1:100 showing inhibition of 0.5mm for Proteus alone.

There was outright resistant by all organisms with the aqueous extract of the leaf. From the investigation carried out it can be seen that Chromolaenaodorataleaf is a potential antimicrobial agent and effective only when used in organic solvent at a higher concentration. Ethanol alone has shown insignificant sensitivity for the organisms under investigation.