Parenteral Lipid Emulsion Induces Germination of Candida albicans and Increases Biofilm Formation on Medical Catheter Surfaces

Background. The administration of parenteral nutrition, including lipid emulsion ( LE), to patients via medical catheters is an unexplained risk factor for the development of candidemia. Germination and biofilm formation are recognized virulence determinants of Candida albicans. No studies have addressed the effect of LE on candidal biofilm production. In this study, we investigated the effect of LE on candidal germination and its ability to form biofilm on medical catheter material. Methods. C. albicans strain SC-5314 was grown in standard growth medium in the presence or absence a commercially available LE. Biofilms grown on silicone-elastomer catheter discs in these media were compared for mass by dry weight measurements. Biofilm morphology was analyzed by scanning electron microscopy and confocal laser microscopy. The effect of LE on C. albicans germination and growth was evaluated microscopically and by determination of colony-forming units, respectively. Results. Addition of LE to standard growth medium increased C. albicans biofilm production and resulted in observed changes in biofilm morphology and architecture. Furthermore, LE induced germination and supported the growth of C. albicans. Conclusions. LE-inducible candidal virulence determinants, such as germination and enhanced biofilm production, may help to explain the increased risk of candidemia in patients receiving LE via medical catheters.