Antifungal resistance in oral Candida: Phenotypic susceptibility, genomic surveillance, and novel postbiotic-based therapeutic strategies.

Oral candidiasis is a common mucosal fungal infection, with Candida albicans remaining predominant alongside increasing recognition of non-albicans Candida species. Reduced antifungal susceptibility and resistance complicate laboratory diagnosis and treatment. This review summarizes current approaches to antifungal resistance characterization in oral Candida, including phenotypic susceptibility testing, molecular detection of resistance determinants, and whole-genome sequencing for strain characterization and genomic surveillance. Particular emphasis is placed on biofilm-associated tolerance, phenotypic adaptation, and mechanisms underlying reduced susceptibility. Emerging postbiotic-based strategies, including cell-free supernatants, bacteriocins, organic acids, biosurfactants, and extracellular vesicles, are also examined for their experimental activity against Candida growth, morphogenesis, adhesion, and biofilm formation. Integrating phenotypic and genomic approaches may strengthen resistance surveillance, while postbiotics warrant further standardized evaluation and clinical validation.