Toward inclusive microbial monitoring: The case for pathogenic yeast surveillance in South African groundwater

• Reviews yeast diversity in South African groundwater sources • Examines health risks of groundwater contaminated with yeasts • Identifies gaps in current microbial monitoring standards • Recommends adding yeasts to groundwater quality assessments • Links human activity and climate to increased yeast presence Groundwater is a critical resource for millions of people worldwide, particularly in rural and semi-arid regions where it serves as the primary source of drinking water. However, microbial contamination, including pathogenic yeasts, remains an overlooked public health concern. Current water quality regulations primarily focus on bacterial indicators, neglecting the potential risks of fungi, particularly yeasts, such as Candida, Cryptococcus, Candidozyma and Rhodotorula . These yeasts can cause various health issues, from mild skin infections to life-threatening systemic disease, especially in immunocompromised individuals. Climate change, agricultural runoff, and improper waste disposal exacerbate groundwater contamination and increase the risk of waterborne infections. This review explores the presence, diversity, and health implications of yeasts in groundwater while assessing their potential as emerging contaminants. Traditional yeast identification methods, including culture-based and biochemical assays, are often time-consuming and have limited sensitivity. Recent advances in molecular technologies, particularly next-generation sequencing (NGS), Oxford Nanopore sequencing, and metagenomics, offer more precise and high-throughput approaches for detecting culturable and nonculturable yeasts in groundwater. By integrating these advanced molecular techniques into routine water quality monitoring, this review highlights the need to revise the water safety regulations to include yeasts as key microbial indicators. Strengthening yeast surveillance in groundwater is essential to ensure public health protection, particularly in regions dependent on untreated water sources.