latrunculin-a and Cryptococcosis

This basic research aimed to investigate the effects of the actin inhibitor latrunculin A (LA) on the human pathogen Cryptococcus neoformans, by freeze-substitution (FS) and electron microscopy (EM), to determine whether the actin cytoskeleton can become a new antifungal target for inhibition of cell division.. Cells treated with LA for 20 h in yeast-extract peptone dextrose medium were investigated by phase-contrast and fluorescent microscopy, FS and transmission EM, counted in a Bürker chamber and the absorbance was then measured.. The disappearance of actin patches, actin cables and actin rings demonstrated the response of the cells of C. neoformans to the presence of the actin inhibitor LA. The removal of actin cables and patches arrested proliferation and led to the production of cells that had ultrastructural disorder, irregular morphology of the mitochondria and thick aberrant cell walls. Budding cells lysed in the buds and septa.. LA exerts fungistatic, fungicidal and fungilytic effects on the human pathogenic yeast C. neoformans.

Topics: Actin Cytoskeleton; Actins; Antifungal Agents; Bridged Bicyclo Compounds, Heterocyclic; Cell Division; Cell Proliferation; Cell Wall; Cryptococcosis; Cryptococcus neoformans; Humans; Microscopy, Electron; Microscopy, Fluorescence; Thiazolidines