Antifungal activity of Streptomyces sp. against environmental and clinical Cryptococcus spp. isolates

M. Ouargli, D. Gacemi-Kirane,

Abstract

This study aimed to analyze the antifungal suscepti bility profile of environmental Cryptococcus spp. a nd to determine the antifungal activity of bioactive mole cules extracted from an actinomycete, strain E96, a gainst these Cryptococcus spp. Cryptococcus strains were investi gated from pigeon droppings, atmospheric air and li ving materials collected on Eucalyptus trees. The isolat es were identified and compared for their sensitivi ty to antifungal agents to clinical strains of Cryptococcus neoforma ns. Actinomycetes were isolated from Mellah Lake wa ter and screened for antimicrobial activity. Antimicrobial assays were performed on ISP2 agar. The taxonomic p osition of the strain E96 was determined regarding phenotypic and 16S DNA sequences features. It was tested for i ts antifungal activity against the Cryptococcus spp. i solates using both double layers and agar disc diff usion methods. Time course of E96 antifungal metabolites productio n was determined on ISP1, ISP2, GYEA and Bennett cu lture media. The actinomycete E96 strain showed a very pr omising activity against the Cryptococcus spp. stra ins, especially interesting when they are resistant to 5 -fluorocytsine, azole or echinocandins.