ANTIMICROBIAL EFFECT OF THE EXTRACTS OF SELECTED MEDICINAL PLANTS AGAINST SOME MICROORGANISMS ISOLATED FROM POULTRY DROPPINGS

Abstract

Every culture has relied on herbal plants due to the presence of huge variety of natural constituents present which are used for therapeutic purposes. This study assessed the antimicrobial effects of the leaves of selected medicinal plants against some microorganisms isolated from poultry droppings. The crude leaf extracts were obtained using maceration. The phytochemical composition of the crude extracts was also analysed. Antimicrobial activity of the extracts was tested against the isolated microorganisms using agar well diffusion and agar dilution. The Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC) were done using broth macrodillution assay. The microorganisms isolated from poultry droppings were Staphylococcus aureus, Salmonella Typhi, Aspergillus niger and Candida albicans. The aqueous leaf extract of Azadirachta indica revealed the maximum antibacterial activity at concentration of 400mg/mL against Staphylococcus aureus (21.0±1.0), Salmonella Typhi (26.0±1.0mm), as compared to other extracts; hence it was found to be the most active extract. The methanol fraction of Azadirachta indica showed the highest antibacterial activity against Salmonella Typhi (18.0±1.0) while the aqueous fraction of of Azadirachta indica showed the highest antibacterial activity against Staphylococcus aureus (16.0±1.0). The aqueous leaf extract of Azadirachta indica revealed the maximum antifungal activity at concentration of 400mg/mL against Candida albicans as compared to other extracts. The fractions had no activity on Aspergillus niger, hence they were resistant to all the four fractions. The MIC of the aqueous extract of Azadirachta indica against S. aureus, S. Typhi, C. albicans was 31.25mg/mL respectively. MBC of 125mg/mL was recorded against C. albicans and S. aureus respectively while 250 mg/mL was recorded against S. Typhi. The aqueous and methanol fractions of Azadirachta indica had MIC of 31.25mg/mL against S. aureus while the methanol and ethyl acetate fractions had MIC of 62.5 mg/mL against S. Typhi. The fractions had MBC of 125 mg/mL for both organisms. The results of this study showed that Azadirachta indica, Allium sativum, Moringa oleifera and Jatropha curcas possess antimicrobial potentials and may be useful in treating infections caused by pathogenic isolates.