Affiliation: Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga, 2752, 90610-000, Porto Alegre, Brazil and Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 43431, 91501-970, Porto Alegre, Brazil.
Staphylococcus epidermidis, a commensal microorganism at the human skin and mucosae, is nowadays considered an important opportunistic pathogen related to nosocomial infections on indwelling medical devices due biofilm formation. Bacterial biofilms are the worst aspect in the treatment of infections and now efforts have been made in the search for new molecular entities to overcome this situation. In this work, a compound isolated from marine associated fungi was capable to interfere with the adherence and biofilm formation of S. epidermidis. This compound, identified as mevalonolactone, showed significant inhibition of S. epidermidis ATCC 35984 biofilm formation, without antibacterial activity, evaluated by crystal violet assay, turbidimetric assay and scanning electron microscopy. When assayed against 12 clinical isolates of S. epidermidis, this compound exhibited both biofilm inhibition and antimicrobial activity, but no activity against gram-negative bacteria was observed. Therefore, when this constitutive molecule is added in the antibiofilm and antibacterial assays, it might act as an important agent against this pathogen, contributing to the arsenal of antibiofilm compounds.