[The fascinating world of free-living amoebae, these remarkably versatile protists].

Free-living amoebae, microorganisms with variable forms, are essential to the ecology. However, some species, such as Naegleria fowleri, Acanthamoeba spp., and Balamuthia mandrillaris, cause severe, though rare, infections including meningitis and keratitis, which are often linked to water. Free-living amoebae are also reservoirs and vectors of various pathogens (bacteria, viruses, and fungi), which facilitates their dissemination and the potential emergence of diseases. Free-living amoebae can also be used as models to study interactions between eukaryotes and prokaryotes. This review explores the ecological, scientific, and pathogenic roles of free-living amoebae and their implications for public health.