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 ATCC 2001 was selected to this study. Several
antifungal drugs, belonging to different groups, were used in this work,
namely fluconazole, voriconazole, amphotericin B, caspofungin and
micafungin and their effect on biofilm matrix was assessed. Biofilm matrix
chemical composition and structure was evaluated by analytical methods,
specifically by HPLC and mass spectroscopy.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 diffusion profiles, explaining the
different tolerance registered. So, with this study we confirmed that C.
glabrata biofilms resistance to antifungal drugs is a very complex
mechanism, where the matrix plays a major role