LOCALIZATION OF PERSISTENT ENTEROCYTOZOON-BIENEUSI INFECTION IN NORMAL RHESUS MACAQUES (MACACA-MULATTA) TO THE HEPATOBILIARY TREE

Enterocytozoon bieneusi is the most common microsporidian parasite rec ognized in human patients with AIDS. Recently, we identified a virtual ly identical organism causing a spontaneous infection associated with hepatobiliary and intestinal disease in simian immunodeficiency virus (SIV)-infected macaques. To examine the natural history of the infecti on, we examined captive rhesus macaques for E. bieneusi by PCR, in sit u hybridization, and cytochemical techniques. PCR performed on fecal D NA detected enterocytozoon infection in 22 (16.7%) of 131 normal rhesu s macaques (Macaca mulatta), compared to 18 (33.8%) of 53 rhesus macaq ues experimentally inoculated with SIV. In normal rhesus macaques, per sistence of infection was demonstrated for up to 262 days and was usua lly not associated with clinical signs. In six of seven normal rhesus animals, E. bieneusi was detected by PCR in bile obtained through perc utaneous cholecystocentesis but not by in situ hybridization performed on endoscopic biopsies of duodenum and proximal jejunum.