Alkylamidobetaines Induced Changes in Multidrug-Resistant, Biofilming Candidaglabrata-Analysis of Oxidative Stress and Cellular Proteome.

Antibiofilm strategies targeting Candida glabrata increasingly focus on membrane-active compounds capable of disrupting biofilm formation and mature biofilm structure. Building on previous work identifying alkylamidobetaine C9 (AAB C9)-[(3-decanoylmethylamino)propyl]dimethylammonium acetate-and β-escin as antibiofilm agents against C. glabrata, this study examined the biochemical and physiological basis of their efficacy in a reference strain (ATCC 90030) and a clinical isolate (2586). Oxidative stress was assessed microscopically after two hours of exposure, and proteome changes were quantified after six hours, for each compound alone and in combination. Fluorescence microscopy showed that AAB C9 and β-escin interacted differently depending on the ROS compartment and strain: in the strain ATCC 90030, the combination antagonized β-escin-induced mitochondrial superoxide, whereas in the multidrug-resistant isolate 2586 it exceeded either agent alone for both cytosolic and mitochondrial superoxide, indicating a strain-dependent, additive interaction. Quantitative proteomics showed that strain genetic background, rather than treatment, was the dominant source of proteome variance. Preranked gene set enrichment analysis revealed that AAB C9 significantly suppressed accumulation of biofilm-formation-associated proteins specifically in isolate 2586, corroborating its phenotypic antibiofilm activity, while β-escin and the combination produced opposing transmembrane-transport signatures, pointing to compound-specific mechanisms underlying their differential antifungal and antibiofilm effects.