Transmission and Serial Propagation ofEnterocytozoon bieneusifrom Humans and Rhesus Macaques in Gnotobiotic Piglets

ABSTRACTFor over a decade Enterocytozoon bieneusiinfections in people with AIDS have been linked with chronic diarrhea and wasting. The slow scientific progress in treating these infections is attributed to the inability of investigators to cultivate the parasite, which has also precluded evaluation of effective therapies. We report here successful serial transmissions of E. bieneusifrom patients with AIDS and from macaques with AIDS to immunosuppressed gnotobiotic piglets. One infected piglet was still excreting spores at necropsy 50 days after an oral challenge. Spores in feces were detected microscopically by trichrome stain and by PCR and within enterocytes by in situ hybridization and immunohistochemistry. E. bieneusiinfection induced no symptoms. The development of an animal model forE. bieneusiwill open up new opportunities for investigating this parasite.