ABSTRACT

The aim of this study was to evaluate the antibacterial activities of selected plants vernonia amygdalina (Bitter leaf), gongronema latfoiium (Utazi) and garcinia kola (Bitter kola leaf) extracts against fish pathogenic bacteria. The freshly collected leaves and seed were washed under the tap water and then distilled water to remove the external impurities. Then they were sliced into small pieces and shade dried for two weeks and then blended into powder using mortar. The powdered leaves of plant extracts were separately extracted with different solvents like water, ethanol and methanol for 24h. The crude extracts were obtained by filtration using Whatman No. 1 filter paper and concentrated by using a rotary evaporator and used for further tests. The bacteria isolated from the fish gills, heart, intestine and pond water sample were Escherichia coil, Kiebsiella spp. Shigeila spp., Staphylococcus . aurues and Pseudomonas spp. The percentage occurrence of bacterial isolates from fish samples shows that Escherichia coil, 35.4% showed the highest percentage occurrences while Pseudomonas 12.3% showed the least percentage occurrence. The methanol extracts of the selected plants showed that Bitter kola leaf l5mg/ml had more antimicrobial activity against Shigeila specie at 200mg/ml while Escherichia coil had the lowest antimicrobial activity of 11mg/ml against Utazi leaf. The ethanol extracts of the selected plants showed that Utazi leaf 14mg/mi had more antimicrobial activity against Staphylococcus aureus at 200mg/ml while Kiebsielia spp had the lowest antimicrobial activity of 10 mg/ml against Utazi leaf. The aqeous extracts of the selected plants showed that Utazi leaf 14mg/ml had more antimicrobial activity against Staphylococcus aureus at 200mg/mi followed while Kiebsiella spp had the lowest antimicrobial activity of 10 mg/ml against Utazi leaf. The minimum inhibitory concentration value of the plant extracts showed more activity against Kiebsiella spp 12.5m1/mg in the ethanol extract while Shigella showed least concentration of 12.5m1/mg on methanol extracts while Staphylococcus aureus showed 12.5m1/mg respectively on Water extract. The selected plant can be of immense use in phytomedicine and can be included in health care delivery system particularly in the developing economies. It can be concluded from this study that the extracts from Utazi Leaf and Bitter Kola leaf showed antimicrobial activity against the tested isolates at high concentration. This probably justifies its use as an antimicrobial agent.