Fungal biofilm inhibition by a component naturally produced by Candida albicans yeasts growing as a biofilm

The purpose of this work was to demonstrate production by the Candida yeasts growing as a biofilm of a compound that reduces candidal biofilm growth. An in vitro model of Candida albicans biofilm associated with silicone catheters was used. Supernatant medium recovered from 24-h-old C. albicans (ATCC 3153) biofilm (S24h) was added during the course of new biofilm formation by four C. albicans strains (182, 444, 2091 or ATCC 3153). Addition of S24h to adherent C. albicans cells induced an inhibition of biofilm growth (P < 0.001) but displayed no activity on established biofilms. Ultrafiltration and purification assays demonstrated that the antagonistic molecule is hydrophilic and <3000 Da in size.