Influence of glucose concentration on the structure and quantity of biofilms formed by Candida parapsilosis

Candida parapsilosis is nowadays an emerging opportunistic pathogen and its increasing incidence is part related to the capacity to produce biofilm. In addition, one of the most important C. parapsilosis pathogenic risk factors includes the organisms' selective growth capabilities in hyperalimentation solutions. Thus, in this study, we investigated the role of glucose in C. parapsilosis biofilm modulation, by studying biofilm formation, matrix composition, and structure. Moreover, the expression of biofilm-related genes (BCR1, FKS1 and OLE1) was analysed in the presence of different glucose percentages. The results demonstrated the importance of glucose in the modulation of C. parapsilosis biofilm. The concentration of glucose had direct implications on the C. parapsilosis transition of yeast cells to pseudohyphae. Additionally, it was demonstrated that biofilm-related genes BCR1, FKS1, and OLE1 are involved in biofilm modulation as a result of glucose. The mechanism by which glucose enhances biofilm formation is not fully understood; however, with this study we were able to demonstrate that C. parapsilosis responds to stress conditions caused by elevated levels of glucose by upregulating genes related to biofilm formation (BCR1, FKS1 and OLE1).