Enterocytozoon bieneusi, a human pathogen

Although brought to the forefront in the 1980s with the AIDS pandemic, microsporidia infecting humans are still little known. Enterocytozoon bieneusi, by far the most frequent microsporidia species causing diseases in humans, is responsible for intestinal illness in both non- and immunocompromised patients. This species presents an astonishing genetic diversity with more than 500 genotypes described, some of which have a strong zoonotic potential. Indeed, E. bieneusi infects a broad array of hosts, from wild to domestic animals. This emerging eukaryotic pathogen has thus been associated with foodborne/waterborne outbreaks. Several molecular assays have been developed to enhance its diagnosis or for epidemiological purposes, providing valuable new data. Here, we propose an overview of the current knowledge on this major species among the microsporidia, so far rather neglected in human medicine.