Created: Friday, 30 June 2017 13:37
Rodrigues, CF; Rodrigues ME; Silva, SC; Azeredo, J; Henriques, M
BIOFILMS'7- Internation Congress of Biofilms, Porto, Portugal, June, 2016.
Candida infections are often associated to biofilms and consequently to high resistance to the most common drugs. These resistance mechanisms are not only associated with the biofilm yeast physiology, but also with the presence of a barrier imposed by the biofilm matrix. However, the biochemical role of the biofilm components remains very unclear. Therefore, this work intends to further enlighten the effect of antifungal agents on C. glabrata biofilm resistance. As a good biofilm former, Candida glabrata ATCC2001 was selected to this study. Several antifungal drugs, belonging to different groups, were used in this work, namely fluconazole, amphotericin B, caspofungin and micafungin and their effect on biofilm matrix was assessed. Biofilm matrix chemical composition and structure was evaluated by analytical methods. As expected, C. glabrata biofilms were resistant to the antifungals used in an agent-dependent manner. The results showed significant differences in polysaccharides and proteins contents, in the matrix of biofilms formed in the absence and in the presence of the drugs. Moreover, the diffusion through the matrix was evaluated demonstrating that different agents, even belonging to the same group, present very different profiles, explaining the different tolerance registered. So, with this study we confirmed that C. glabrata biofilm’s resistance to antifungal drugs is a very complex mechanism, where the matrix plays a major role.
The biofilm matrices of C. glabrata ATCC2001 strongly changes when in contact to antifungal drugs: protein profile changes and β-1,3 glucans production increases.
It is known that β-1,3 glucans are linked to the antifungal resistance, by making it difficult to the drugs to diffuse through the biofilm matrices and reach the yeast cells. This change in the matrix composition may be an attempt of the cells to obtain a denser matrix, unflexible and more protective for their environment.