Culture conditions which lead to swelling and germination of Aspergillus fumigatus conidia dramatically influenced cell surface characteristics, such as hydrophobicity, agglutination, molecular composition and biological rearrangements of the cell wall. Adherence of conidia to polystyrene, like autoagglutination of conidia, markedly increased during swelling, in a time-dependent manner. Agglutination appeared cyclohexamide and calcium sensitive. Lyticase, dithiothreitol and sodium metaperiodate abolished agglutination of cells, whereas proteinase-K weakly decreased it. Electron microscopic observations suggested that the cell wall of conidia was subject to some rearrangements during swelling, involving degradation and lost of the external convoluted layer, and subsequent presentation of underlaying ligands. This was confirmed using gold or FTTC-labeled lectins which showed that some carbohydrates, more particularly those acting as ligands for peanut agglutinnin, are largely exposed during swelling. Finally, SDS-PAGE revealed major protein changes betweem resting and swollen conidia. We conclude that the ability of #a. fumigatus conidia to adhere and to aggregate correlates with an increase of hydrophobicity and biological reorganisation of their cell wall.
Full conference title:
The 2nd Meeting of the European Confederation of Medical Mycology
- ECMM 2nd (1995)