Antibacterial Effect of Gongronema latifolium Leaf Extract on Staphylococcus aureus Isolates from Skin of Human Subjects in Lafia Metropolis

Antibiotics have been critical in the fight against infectious diseases. However, plants have also been used to treat diseases due to presence of some chemical compounds (active ingredients) that possess medicinal properties. This study investigated the antibacterial effect of Gongronema latifolium (amaranth globe) leaf extract on staphylococcus aureus isolates from the skin of human subjects in Lafia metropolis, Nasarawa State, Nigeria. Aqueous and ethanol leaf extracts of G. latifolium were screened for antibacterial activity against S. aureus isolates using the agar disk diffusion method. A total of forty specimens were collected and S. aureus was isolated using standard biochemical methods. Hospital isolates had the highest lowest percentage sensitivities of 85.71% and 0.00% from 300 mg/mL ethanol and 200 mg/mL aqueous extracts respectively. Also, restaurant isolates had the highest percentage and lowest sensitivities of 83.33% and 0.00% from 300 mg/mL ethanol and 200 mg/mL aqueous extracts respectively. Both extracts showed significant differences observed in their concentration effects against S. aureus isolates from restaurant subjects (p<0.05). MIC was 75 mg/mL for the aqueous extract against isolates obtained from both sources and that for the concentration ranges of 300-9.375 mg/mL and 200-6.25 mg/mL ethanol extract was observed to be 37.5 mg/mL and 50 mg/mL respectively. The result of the study showed that both extracts of G. latifolium have an inhibitory effect proportional to concentration on the test organism S. aureus isolates obtained from both subjects. Hence, ethanol extract of G. latifolium may potentially control skin respiratory and enteric infections caused by S. aureus.