In-vitro antimicrobial activity of Psidium guajava l. leaf extracts against clinically important pathogenic microbial strains

ABSTRACT

The methanol, acetone and N, N-dimethylformamide (DMF) fractions of leaves of Psidium guajava L. were evaluated for antibacterial and antifungal activity. Piperacillin and gentamicin were used as standards for antibacterial assay, while nystatin and flucanazole were used as standards for antifungal assay. 91 clinically important strains were used for the study which were both clinical isolates as well as identified strains. The antibacterial activity was more pronounced against gram-positive bacterial and fungal strains. Moderate activity was shown against the gram-negative bacterial strains studied.

RESUMO

Os extratos de folhas de Psidium guajava L. preparados com metanol, acetona e N,N-formamida foram avaliados quanto a sua atividade antibacteriana e antifúngica. Piperacilina e gentamicina foram empregadas como padrões de atividade antibacteriana e nistatina e fluoconazol com padrões de atividade antifúngica. O estudo foi desenvolvido com noventa e uma cepas de importância clínica, incluindo isolados clínicos e cepas identificadas. A atividade antibacteriana foi mais intensa contra as cepas de bactérias Gram positivas e de fungos. A atividade contra bactérias Gram negativas foi moderada.