Interaction with amoeba drives virulence-associated phenotypes in the Candida haemulonii complex
- Author: mycolabadmin
- 10/9/2025
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Summary
Researchers discovered that when fungal pathogens called Candida haemulonii are exposed to soil amoebae in laboratory conditions, they develop enhanced disease-causing abilities. These fungi undergo multiple changes including forming stronger protective biofilms, producing more virulence factors, and becoming harder to kill by immune defenses. This suggests that fungal pathogens might develop some of their dangerous traits not from infecting humans, but from surviving in soil environments where they must evade predatory organisms like amoebae.
Background
Candida haemulonii complex species are increasingly prevalent non-albicans Candida pathogens with concerning resistance to antifungal agents. Environmental interactions with predatory organisms like amoebae may drive the evolution of virulence traits in fungi, serving as selective pressures that enhance pathogenic potential.
Objective
This study investigated whether interaction with Acanthamoeba castellanii modulates virulence phenotypes and pathogenic potential of Candida haemulonii complex species isolated from environmental sources.
Results
Amoeba-adapted C. duobushaemulonii isolates developed four distinct phenotypes with increased aggregation and filamentation. Adapted isolates produced over 15-fold more biofilm biomass and exhibited significant upregulation of virulence-associated genes including WOR1, CPH1, HGC1, ALS1, BCR1, and EGF1. Pathogenicity assays showed 71.5-97.1% reduction in lethal dose compared to non-adapted controls.
Conclusion
Environmental interaction with amoebae promotes emergence of virulence-associated phenotypes in C. duobushaemulonii through phenotypic switching, enhanced biofilm formation, increased enzyme production, and improved stress tolerance. These findings suggest that environmental pressures from amoebic predation may facilitate the evolution of fungal pathogenesis.
- Published in:Virulence,
- Study Type:Experimental Laboratory Study,
- Source: 41068557