The Antimicrobial Effects of Local Spices:Onions (Allium Cepa, Garlic (Allium Sativum), Ginger (Zingiber Officinale), and Pepper (Piper Guineense) on Selected Pathogenic Bacteria and Fungus

Abstract

The toxicity of garlic, ginger, pepper, and onion was studied on some clinical isolates. The isolates include: Escherichia coli, Staphylococcus aureus, Salmonella typhi, Bacillus species, and Candida albicans. The crude extracts of the spices were obtained using 99% ethanol, 99% methanol, and hot water (100oc).Different graded concentrations of the extracts (aqueous and alcoholic) were prepared by pipetting one mill of the extract which yielded 100%, one mill of the extract plus one mill of water which yielded 50%, one mill of the extract plus 2 mills of distilled water which yielded 33.3%.The growth inhibitory effects of the aqueous and alcoholic extracts were examined using agar well diffusion method. The extracts were found to possess antimicrobial effects on the isolates by inhibiting their growths on the agar plates used. Hot water extracts of onion exhibited growth inhibitions on Salmonella typhi, Escherichia coli, Staphylococcus aureus, Bacillus species and Candida albicans with a mean of 11mm, 9.67mm, 4.67mm, 7.67mm, and 7mm respectively. Ethanol extracts of garlic exhibited growth inhibitions on Salmonella typhi, Escherichia coli, Staphylococcus aureus, Bacillus species and Candida albicans with a mean of 9.33mm, 7mm, 9.67mm, 9mm, and 11.33mm respectively etc. Organic extracts of methanol exhibited a higher growth inhibition when compared to organic extracts of ethanol, and aqueous extracts.The growth inhibitory effects of the crude extracts were compared with some third generation antibiotics: Ampicillin and Griseofulvin. The conventional antibiotics exhibited greater zones of inhibition compared to the crude extracts. Generally, garlic exhibited a higher growth inhibition when compared to other extracts.