Editing Candida: Origins and Advances of CRISPR Tools

Pathogens causing candidiasis encompass a diverse group of ascomycetous yeasts that have become essential models for studying fungal adaptability, pathogenicity, and host-pathogen interactions. Although many candidiasis-promoting species exist as commensals within host microbiota, several have acquired virulence traits that enable opportunistic infections, positioning them as a leading cause of invasive fungal disease in humans. Deciphering the molecular and genetic determinants that underpin the biology of organisms responsible for candidiasis has long been a central objective in medical and molecular mycology. However, research progress has been constrained by intrinsic biological challenges, including noncanonical codon usage and the absence of a complete sexual cycle in diploid species, which have complicated traditional genetic manipulation. CRISPR-Cas9 genome editing has overcome many of these limitations, providing a precise, efficient, and versatile framework for targeted genomic modification. This system has facilitated functional genomic studies ranging from single-gene deletions to high-throughput mutagenesis, yielding new insights into the mechanisms governing virulence, antifungal resistance, and stress adaptation. Since its initial application in <i>Candida albicans</i>, CRISPR-Cas9 technology has been refined and adapted for other clinically and industrially relevant species, including <i>Nakaseomyces glabratus</i> (formerly referred to as <i>Candida glabrata</i>), <i>Candida parapsilosis</i>, and <i>Candida auris</i>. The present work provides an overview of the evolution of genetic approaches employed in research directed against candidiasis-associated species, with a particular focus on the development and optimization of CRISPR-based systems. It highlights how recent advancements have improved the genetic tractability of these pathogens and outlines emerging opportunities for both fundamental and applied studies in fungal biology.