Evaluaciòn de la actividad antimicrobiana del extracto de Pleurotus ostreatus ante cepas de Escherichia coli y Staphylococcus aureus.

Abstract

The purpose of the present work was to evaluate the antimicrobial activity of the Pleurotus ostreatus extract against the Escherichia coli and Staphylococcus aureus strains. For this study a Pleurotus ostreatus fungus extract was prepared through an alcohol maceration process. The extract was evaluated by conducting a phytochemical screening and a control of the same. The extract was used at different concentrations: 30, 70 and 100%, subsequently for the antimicrobial evaluation the disc diffusion method was used over two bacteria: Escherichia coli (American Type Culture Collection ATCC 9637) and Staphylococcus aureus (ATCC 25923). The activity from the extract was compared with its positive controls: ampicillin (10 ug) and amikacin (30 ug). It was performed under a standard of 0, 5 McFarland and the inoculated plates were incubated at 35°C for 18 to 24 hours. The antimicrobial activity was determined by the presence or lack of inhibition halos and the potency of the extract was estimated by measuring the diameters of these halos. The fungus extract at 100% concentration presented a larger halo relative to the others. The Staphylococcus aureus relative to the Escherichia coli showed an inhibition halo much larger. It was concluded that through the evaluation of the antimicrobial activity of the Pleurotus ostreatus extract, we observed that it doesn't present a halo diameter that would justify such activity or at the same time that the halo diameter is less than the minimum range present in bibliography on the strains because a raw extract was used and not with the specific compounds that give it more activity, for which it is recommended to perform an identification of terpene compounds present in the Pleurotus ostreatus fungus because it has the highest antimicrobial activity.