摘要:Prosopis juliflora is the most widespread species of genus Prosopis and it is a good source of compounds that have been shown to be pharmacologically active. This plant has been used as a traditional treatment for several diseases such as microbial infections are major public health problems in the developed and developing countries. Infectious disease is a major cause of deaths accounting for one-half of all deaths in tropical countries. Therefore, this study was carried out to investigate the in vitro antimicrobial activity of Prosopis juliflora methanolic leafs extract against clinical isolates performed by cup-plate agar diffusion method against seven Gram negative bacteria: Escherichia coli, Escherichia coli ESBL, Shigella flexneri, Salmonella typhi, Proteus mirabilis, Pseudomonas aeruginosa, and Klebsiella pneumoniae; and three Gram positive bacteria: Enterococcus faecalis, Listeria monocytogenes and Bacillus cereus. The methanolic extract exhibited inhibitory effects against most of the tested microorganisms with zone of inhibition ranging from 12 to 41 mm. The largest inhibition zone were obtained from methanolic extract of P. juliflora (leaf) against the Gram negative P. aeruginosa (41 mm) in 100 mg/ml concentration, and Gram positive L. monocytogenes (33 mm) in 100 mg/ml concentration in comparison with Gentamicin 10 mgc. The methanol extract of Prosopis juliflora was found effective against different species of bacteria and considered for further exploration and isolation active compounds analysis.