In vitro Antibacterial Activity of Psidium guajava Leaves Extracts against Clinical Isolates of Salmonella specie

Abstract

Dried leaves of Psidium guajava obtained from Bayero University, Kano old campus were extracted using water, ethanol, and chloroform solvents via the percolation method. The leaf extracts were subjected to phytochemical screening to detect the presence of secondary metabolites. The extracts were further tested for antibacterial activity against clinical isolates of Salmonella Typhi, Salmonella Paratyphi A, and Salmonella Paratyphi B using the agar well diffusion method. The results of phytochemical screening indicated the presence of tannins, flavonoids, steroids, terpenoids, and phenols, while those of the antibacterial activity indicated that the highest zone of inhibition was observed in water extracts against S. Paratyphi B (12mm), followed by water extracts against S. Paratyphi A (9.6mm), with the least being water extracts against S. Typhi (8mm). S. Paratyphi B was resistant to both ethanolic and chloroform extracts, while S. Typhi was found to be resistant to chloroform extracts only. S. Paratyphi A was, however, found to be the most sensitive bacterium to all the extracts regardless of the extraction solvent.