This article highlights AFM-based research on drug-resistant microorganisms and their biofilms. The researchers combined AFM with nanoindentation and synchrotron-based ATR-FTIR spectral mapping to quantify the nanomechanical and bio-chemical differences between the mature biofilms of various fungal species: Candida albicans, Cryptococcus neoformans and two antifungal resistant sub-species of C. neoformans.
In this work, the NanoWizard 4 bioAFM and Hysitron TI Premier nanoindenter were used to perform imaging and nanoscale modulus mapping tests, while ATR-FTIR micro-spectroscopy analysed the spatio-chemical composition of the four biofilm systems. The AFM measurements provided high-resolution images and highlighted the morphological differences between the four fungal cell types, suggesting that antifungal resistance in the species studied causes visible and measurable changes in their cellular morphology. Bulk nanoindentation measurements highlighted the difference in the storage modulus values between resistant and sensitive fungal strains, while no significant differences in the surface adhesion of the biofilms of the species were observed.