Antimicrobial Activity of Warburgia ugandensis on Selected Standard Organisms that Cause Urinary Tract Infections

Abstract

Background: The antimicrobial effect of Warburgia ugandensis has been recognized for many years in developing countries especially in East Africa. However, limited investigations have focused on its effect on microorganisms causing urinary tract infection. Objective: To determine the antimicrobial activity of Warburgia ugandensis on selected standard microorganisms that cause urinary tract infections i.e. Escherichia coli (ATCC 25922), Candida albicans (ATCC 10231), Proteus mirabilis (ATCC 25933), and Staphylococcus aureus (ATCC 25923). Methods: Warburgia ugandensis stem bark was obtained from Tooro Botanical centre and were shade dried. The aqueous and ethanolic extracts were prepared and evaluated for phytochemical components using semi qualitative phytochemical screening techniques. The antimicrobial activity on three bacteria; Staphylococcus aureus, Escherichia coli, Proteus mirabilis and one fungus Candida albicans was tested by agar well diffusion and broth dilution which to obtain the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the plant extracts respectively. Results: Phytochemical screening showed the presence of tannins, flavonoids, alkaloids, saponins and terpenoids in both the aqueous and ethanolic extracts. The  bacteria were susceptible to the aqueous extract which caused significant inhibition of microbial growth with the highest activity observed on Staphylococcus aureus (MIC 0.49mg/ml), while less susceptibility to the ethanolic extract was observed with Staphylococcus aureus having an MIC of 1.95mg/ml and so was MBC/MFC, in which Staphylococcus aureus had an MBC of 7.81mg/ml. Candida albicans showed the same pattern with more susceptibility to the aqueous extract (MFC 15.63mg/ml) as compared to the ethanolic extract (MFC 62.5mg/ml) Conclusion: The aqueous and ethanolic extracts of Warburgia ugandensis exhibit antimicrobial effect against the selected urinary tract infection causing organisms. The aqueous extract showed antimicrobial activity in both agar well diffusion and broth dilution methods. This study further shows the potential of Warburgia ugandensis being a novel source of modern drugs with further studies and these results provide some new perspectives on the traditional uses of Warburgia ugandensis in treating urinary tract infections.