Candida albicans morphologies revealed by scanning electron microscopy analysis

Area of Science:

• Mycology
• Microbiology
• Cell Biology

Background:

• Candida albicans is an opportunistic fungal pathogen.
• Morphological switching, including yeast-to-hypha transition, is key to C. albicans virulence.
• Transcription factors Efg1 and Cph1 regulate C. albicans morphology and adhesion.

Purpose of the Study:

• To investigate the roles of EFG1 and CPH1 genes in Candida albicans morphology and virulence.
• To compare the ultrastructural differences between wild-type and mutant C. albicans strains.
• To determine the importance of hyphae formation in C. albicans bloodstream infections.

Main Methods:

• Scanning electron microscopy (SEM) was used to analyze cell morphology.
• Comparative analysis of wild-type C. albicans and mutants lacking EFG1 and/or CPH1 genes.
• Culturing in human serum to induce morphological changes.

Main Results:

• Efg1 is essential for human serum-induced cell growth and morphological switching in C. albicans.
• Mutants lacking EFG1 showed distinct ultrastructural differences, including altered blastoconidia and septa formation.
• Wild-type strains formed true hyphae essential for conglomerate integrity, which mutants lacked, impacting virulence in serum.

Conclusions:

• Efg1 plays a critical role in regulating Candida albicans morphology and virulence.
• True hyphae formation, regulated by Efg1, is vital for C. albicans structural integrity and potential role in bloodstream infections.
• Understanding these morphological pathways can inform strategies against C. albicans infections.