Climate change and free-living amoebae: overlooked accelerators of antimicrobial resistance and virulence at the environment–human interface

Free-living amoebae (FLA), including Acanthamoeba species, Balamuthia, Naegleria and Sappinia, can cause severe human infections. In addition to their direct pathogenicity, they play a role as intracellular reservoirs that protect bacteria, viruses, fungi and protozoa from environmental stress, promoting persistence, virulence, antimicrobial resistance (AMR) and horizontal gene transfer (HGT). Hospitals and aging water systems may provide an ideal environment for these interactions, and increase the risk of emerging healthcare-associated pathogens. In the context of climate change and microbial resilience, integrating FLA into surveillance, genomic monitoring, infection-control policy and AMR research is important to prevent future environmental and clinical threats.