SCREENING OF ACTINOMYCETES WITH ACTIVITY AGAINST CLINICAL ISOLATES OF GRAM POSITIVE COCCI WITH MULTIRESISTANT PROFILE

Abstract

Actinomycetes are Gram-positive bacteria widely distributed in the environment and known for the diverse biologically act ive molecules they produce. This study assesses the activity of compounds produced by 40 actinomycete isolates against Enterococcus spp. Staphylococcus aureus and Staphylococcus epidermidis clinical isoalates. The susceptibility profile of the samples was assessed using the agar disk diffusion method. Antimicrobial activity of actinomycetes was evaluated according to the double layer method. Here, two isolates (50 and 8S) exhibited activity against 90% of clinical Staphylococcus spp. and Enterococcus spp. These isolates were grown in starch casein broth at 30˚C for 7 days with constant shaking. After, the culture obtained was filtered to obtain a crude extract, whose antibiotic activity was assessed using the well diffusion technique. In this assay, isolate 50 presented higher activities than that exhibited by isolate 8S. The isolate 50 has been used in different assays looking for production of metabolite optimization.