Figure 2

Scanning electron microscopy (left column) and transmission electron microscopy (two right columns) micrographs of C. albicans (isolate 77) untreated (Fig. A-C) and treated with MIC ₅₀ of AZA (0.25 μg.ml^-1) (Fig. D-F) and EIL (1 μg.ml^-1) (Fig. G-L) for 48 h at 35°C. Control cells have a normal ultrastructure, with nucleus (n), nucleoli (nu), continuous cytoplasmatic membrane (cm), compact cell wall (cw) with fibrillar structures (f), and several ribosomes in the cytoplasm (Fig. A-C). Treated cells show ultrastructural alterations, such as: presence of small buds (asterisks in Fig. 2D, G and J); cell-wall disruption (black and white arrows in Fig. D-J), and increased thickness (cw in Fig. F, I and L); budding of small vesicles coming from the intracellular membranes (arrowhead in Fig. F); accumulation of small vesicles in the periplasmatic region (inset in Fig. F), in cytoplasm (inset in Fig. I), and in close association with the cytoplasmatic membrane (inset in Fig. L); accumulation of electron-dense vacuoles (v in Fig. K) and mitochondrial swelling (m in Fig. K). The effect of 24-SMT inhibitors on cell size and on cell wall thickness was measured and statistically analysed (Fig. M and N, respectively). Bars in A, D, G, and J = 5 μm; B, E, H, and K = 1 μm; C, F, I, and L = 0.2 μm. * p < 0.01; **p < 0.001; ***p < 0.0001.