This work was aimed at assaying the in-vitro effect of aqueous and ethanolic leaf extracts of Gongronema latifolium on Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli. Six (6) milimetre sterile discs were impregnated with the aqueous and ethanolic extracts at different concentrations ranging from 6.25mg/mL to 100mg/mL. The test organisms were spread evenly on Mueller Hinton agar plate and the discs were aseptically placed on them. The sensitivity plates were incubated at 37ºC for 24 hours. All the test organisms showed sensitivity to both aqueous and ethanolic leaf extracts of Gongronema latifolium. The zones of inhibition were concentration dependent, ranging from 2.0mm to 10.8mm for aqueous extract and 2.0mm to 8.3mm for the ethanolic extract. Comparison of the zones of inhibition produced by the two extracts showed that there is no statistical difference (P > 0.05) between aqueous and ethanolic extracts. Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae had Minimum inhibitory concentration (MIC) of 6.25mg/mL, while Pseudomonas aeruginosa had MIC of 25mg/mL for the aqueous extract. The MIC was 3.125mg/mL, 6.25mg/mL, 6.25mg/mL and 25mg/mL for S. aureus, E. coli, K. pneumoniae and P. aeruginosa, respectively for the ethanolic extract. Gongronema latifolium extracts were also bactericidal in action. S. aureus, E. coli and P. aeruginosa all had Minimum bactericidal concentration (MBC) of 6.25mg/mL, while K. pneumoniae had MBC of 25mg/mL for the aqueous extract, while for the ethanolic extract, S. aureus, E. coli, K. pneumoniae and P. aeruginosa had MBC of 12.5mg/mL, 12.5mg/mL, 6.25mg/mL and 3.125mg/mL respectively. The data obtained from the study indicated that both the aqueous and ethanolic leaf extracts of Gongronema latifolium possess antibacterial properties. Therefore, the pharmaceutical industries should consider its usage for the production of novel antibiotics.
Keywords: : Antibiotic, Plants, Pseudomonas aeruginosa, Resistance, medicinal
