The Candida pathogenic species complex

Area of Science:

• Mycology
• Medical Microbiology
• Genomics

Background:

• Candida species are leading causes of fungal infections globally.
• Five species (Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, Candida krusei) account for most infections.
• Three species belong to the CTG clade, characterized by non-standard codon translation.

Purpose of the Study:

• To investigate the genomic basis of virulence in pathogenic Candida species.
• To understand the evolutionary processes contributing to the rise of specific Candida species, such as Candida glabrata.
• To explore the role of gene family expansion and loss in Candida pathogenicity.

Main Methods:

• Comparative genome analysis of key Candida species.
• Identification of gene families, with a focus on cell wall genes.
• Analysis of evolutionary events such as gene loss and expansion.

Main Results:

• Virulence in the CTG clade is associated with the expansion of gene families, particularly those encoding cell wall components.
• Similar evolutionary processes, including gene loss and expansion, were observed in the Candida glabrata species group.
• These genomic changes in Candida glabrata ancestors may have conferred preadaptations for pathogenicity.

Conclusions:

• Gene family expansion, especially in cell wall genes, is a significant factor in Candida virulence.
• Independent evolutionary trajectories involving gene gain and loss have shaped pathogenicity in different Candida lineages.
• Understanding these genomic mechanisms is crucial for addressing the increasing incidence of drug-resistant Candida infections.