Antibacterial Activity of the seed of Dialium guineense  against Selected Enteric Bacteria

This study was aimed at evaluating the antibacterial activity and screening the phytochemical composition of the seed of Dialium guineense. The aqueous, methanolic and ethanolic extracts of the seed of Dialium guineense were analyzed against some clinical isolates. The phytochemical composition and antibacterial sensitivity testing were carried out using standard methods. The clinical isolates were Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae and Salmonella typhi. Broad spectrum antibiotics were used as positive control for the antibiotic sensitivity test. Phytochemical screening of the extracts revealed the presence of saponin, tannins, alkaloid and glycoside while antimicrobial activity test at various concentrations for ethanolic and methanolic extracts showed significant results against the selected enteric bacteria with the exception of aqueous extracts which showed no antimicrobial activity against any of the isolates. The highest zone of inhibition (13.33mm) was obtained against S. typhi using methanolic extract while E. coli had a zone of inhibition of 10.67mm using ethanolic extract. P. mirabilis showed the lowest zone of inhibition (3.67mm) using ethanolic extract. Ciprofloxacin showed the highest sensitivity to the test organisms while Gentamicin showed the lowest sensitivity. MIC results for the methanolic and ethanolic seed extract against the microbial isolates varied. However, a higher concentration above 225 mg/ml would be required for bactericidal activity, From these findings, the seed of Dialium guineense is a potential source of bioactive compounds and may have implications in the management of infectious diseases caused by some enteric bacteria.