Background: The increased prevalence of antibiotic resistance, as a result of extensive antibiotic use, may render the current antimicrobial agents insufficient to control, at least, some bacterial infections. Methods: The aerial part of plant of Psidium guajava L. was extracted by maceration with Ethanol (99.9% v/v) to exhaustion. the solvent was evaporated under reduced pressure. To evaluate antimicrobial activity, the Kirby Bauer disc diffusion method assay was used against Gram-positive bacteria (Staphylococcus aureus). Results: The dry extract alone did not show any inhibitory effect on the tested bacterial strain. Association of fresh extract and antibiotics and the plant extract showed synergistic antibacterial activity especially with Nitrofurantoin and Septrin-trim. Conclusion: Fresh and dry extract of leaf of Psidium guajava showed antimicrobial activity against clinical isolates of S. aureus ,which showed that this part can be a potential candidate to be used as a therapeutic agent. There for this plant need to further pharmacological studies. There for this plant need to further pharmacological studies.
Keyword: Psidium guajava L – Antibiotic – Antimicrobial – Staphylococcus aureus.