Distribution and Current State of Molecular Genetic Characterization in Pathogenic Free-Living Amoebae.

Free-living amoebae (FLA) are protozoa widely distributed in the environment, found in a great diversity of terrestrial biomes. Some genera of FLA are linked to human infections. The genus is currently classified into 23 genotypes (T1-T23), and of these some (T1, T2, T4, T5, T10, T12, and T18) are known to be capable of causing granulomatous amoebic encephalitis (GAE) mainly in immunocompromised patients while other genotypes (T2, T3, T4, T5, T6, T10, T11, T12, and T15) cause keratitis mainly in otherwise healthy patients. Meanwhile, is the causative agent of an acute infection called primary amoebic meningoencephalitis (PAM), while , like some genotypes, causes GAE, differing from the latter in the description of numerous cases in patients immunocompetent. Finally, other FLA related to the pathologies mentioned above have been reported; sp. is responsible for one case of amoebic encephalitis; has been found in cases of ocular damage, and its extraordinary capacity as endocytobiont for microorganisms of public health importance such as , and , among others. This review addressed issues related to epidemiology, updating their geographic distribution and cases reported in recent years for pathogenic FLA.