Chemical-Genetic Approaches for Exploring Mode of Action of Antifungal Compounds in the Fungal Pathogen Candida albicans.

Candida albicans is a prevalent fungal pathogen of humans that can cause both superficial and life-threatening disease, primarily in immunocompromised populations. Currently, antifungal drug classes available to treat fungal infections remain limited and the emergence of drug-resistant strains threatens antifungal efficacy, necessitating the discovery and development of additional therapeutics. The construction of the C. albicans double-barcoded heterozygous deletion collection (DBC) enables the rapid and systematic assessment of haploinsufficiency phenotypes in a pooled format. Specifically, this functional genomics resource can be used to identify heterozygous deletion mutants that are hypersensitive to compounds in order to define putative cellular targets and/or other modifiers of compound activity. Here, we describe protocols to characterize the mode of action of small molecules using the C. albicans DBC, including how to prepare compound-treated cultures, isolate genomic DNA, amplify strain-specific barcodes, and prepare DNA libraries for high-throughput sequencing. This technique provides a powerful approach to elucidate the compound mechanism of action in order to bolster the antifungal pipeline.