Journal of Antimicrobial Agents

Antimicrobial Activity of Moringa oleifera, Aloe vera and Warbugia ugandensis on Multi-Drug Resistant Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus

Abstract

Muhuha AW, Kang’ethe SK and Kirira PG

Multi-drug resistant is a global public health concern. There has been an increase in infections caused by multidrug resistant micro-organisms in Sub Saharan Africa. This has led to extended illness, expensive health care and deaths. This experimental study was aimed to determine the anti-microbial activity of aqueous and methanol leaf extracts of Warbugia ugandensis, Moringa oleifera and Aloe vera on standard bacteria and multi-drug resistant clinical isolates of Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. Tetracycline drug was used as the reference drug. The bacteria were treated with extracts at different concentrations to determine the zones of inhibition through Agar Diffusion Assay, minimum inhibitory concentration and minimum bactericidal concentration assays. Raw data was analyzed using one-way and two-way analysis of variance followed by Tukey’s post hoc test. Zones of inhibition ranged from 6.5 mm to 9.98 mm on the multi-drug resistant isolates, while those of the standard bacteria ranged from 6.5 mm to 12.00 mm. Methanol extracts of W. ugandensis, M. oleifera and A. vera at the concentration of 400 mg/ml had higher zones of inhibition against multi-drug resistant S. aureus, P. aeruginosa and E. coli respectively. The antimicrobial activity of the extracts indicated a concentration-dependent response. The minimum bactericidal concentration values obtained were double the minimum inhibitory concentration values. Methanol extracts recorded lower minimum inhibitory and minimum bactericidal concentrations compared to aqueous extracts. Phytochemicals which were present, included alkaloids, cardenolide glycosides, phenols, flavonoids, coumarins, tannins, saponins and anthracin glycosides. These phytochemicals are associated with antimicrobial activities. This study showed potent antimicrobial activities of methanol and aqueous extracts of W. ugandensis, M. oleifera and A. vera against the multi-drug resistant and standard bacteria tested. The extracts, therefore, may be used to develop alternative therapeutics in the management of multi-drug resistant Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli.