Current microbiological challenges in drinking water

Drinking water (DW) is paramount to human health, serving as a cornerstone of public health worldwide. However, DW is not a sterile product and can harbor a large diversity of microorganisms, including pathogens. This comprehensive review addresses the critical importance of DW for human health and the ongoing challenges posed by microbial pathogens and biofilms in water distribution systems. It further analyzes the growing challenges driven by contemporary factors such as antimicrobial resistance, biofilms, climate change, and micropollutants. Biofilms, in particular, remain underestimated in conventional water treatment processes despite their significant contribution to microbial contamination, the formation of disinfection by-products, and disinfectant resistance. Emerging challenges, such as climate change and micropollutants, have become significant concerns due to their profound impact on microbial communities and their role in shaping biofilm formation. This review highlights the key microbiological threats to DW distribution systems, focusing on the role of biofilms and the emerging challenges posed by climate change. It explores the factors promoting biofilm development, including water composition, pipe materials, and treatment strategies. It also explores the limitations of current water treatment strategies, which often fail to address biofilms effectively, and highlights the need to integrate microbiological considerations into water quality management. This review aims to underscore the urgent need to reassess water treatment and management practices to address current microbiological challenges and ensure the delivery of safe and sustainable DW. • Microbial pathogens and biofilms pose significant challenges in water systems. • Biofilms act as reservoirs for pathogens, increasing contamination risks. • Emerging pathogens and biofilm resilience complicate maintaining water safety. • Ongoing surveillance is crucial for early detection of waterborne diseases. • Research is needed on biofilms, disinfection and disinfection by-products formation.