OBJECTIVE: To Demonstrate the in vitro antibacterial effect of the alcoholic extract of Vaccinium corymbosum L. on Escherichia coli and Staphylococcus aureus. MATERIAL AND METHOD: 2 Kg of Vaccinium corymbosum L. fruit was collected from Virú, La Libertad; the alcoholic extract was obtained by the method of maceration with ethanol at 70% for concentrations of 25%, 50%, 75% and 100%, determining the antibacterial effect by means of the Kirby and Bauer disc diffusion method, quantified by the Duraffourd’s scale, furthermore, control drugs were used to compare the antibacterial effect: Oxacillin for Staphylococcus aureus and ciprofloxacin for Escherichia coli. RESULTS: The results showed that there was antibacterial effect in all the concentrations of the alcoholic extract of Vaccinium corymbosum L. for Escherichia coli, and for Staphylococcus aureus only the concentration of 25% did not present antibacterial effect (7.5 mm). It was evidenced that the control drugs obtained greater halo of inhibition than the concentrations of the extract (22.2 mm for Staphylococcus aures and 36.6 mm for Escherichia coli). There was a greater antibacterial effect on Staphylococcus aureus than on Escherichia coli. CONCLUSION: The alcoholic extract of Vaccinium corymbosum L. has an antibacterial effect on Escherichia coli and Staphylococcus aureus.OBJETIVO: Demostrar el efecto antibacteriano in vitro del extracto alcohólico de Vaccinium corymbosum L. sobre Escherichia coli y Staphylococcus aureus. MATERIAL Y MÉTODO: Se recolectaron 2 Kg de fruto de Vaccinium corymbosum L. procedente de Virú, La Libertad; se obtuvo el extracto alcohólico mediante el método de maceración con etanol a 70% para concentraciones de 25%, 50%, 75% y 100%, determinando el efecto antibacteriano mediante el método de difusión de discos de Kirby y Bauer, cuantificándose mediante la escala de Duraffourd, además se utilizaron fármacos controles para comparar el efecto antibacteriano: Oxacilina para Staphylococcus aureus y ciprofloxacino para Escherichia coli. RESULTADOS: Los resultados mostraron que hubo efecto antibacteriano en todas las concentraciones del extracto alcohólico de Vaccinium corymbosum L. para Escherichia coli, y para Staphylococcus aureus sólo la concentración de 25 % no presentó efecto antibacteriano (7.5 mm). Se evidenció que los fármacos controles obtuvieron mayor halo de inhibición que las concentraciones del extracto (22.2 mm para Staphylococcus aureus y 36.6 mm para Escherichia coli). Hubo mayor efecto antibacteriano sobre Staphylococcus aureus que sobre Escherichia coli. CONCLUSION: El extracto alcohólico de Vaccinium corymbosum L. posee efecto antibacteriano sobre Escherichia coli y Staphylococcus aureus.Tesis