Am J Pathol. 1997 Apr;150(4):1395-405. Unique Identifier : AIDSLINE
Enterocytozoon bieneusi is a common opportunistic pathogen of human
patients with acquired immune deficiency syndrome (AIDS) causing
significant morbidity and mortality. In a retrospective analysis
utilizing conventional histochemical techniques, in situ hybridization,
polymerase chain reaction, and ultrastructural examination, we
identified 18 simian-immunodeficiency-virus-infected macaques (16 Macaca
mulatta, 1 M. nemestrina, and 1 M. cyclopis) with Enterocytozoon
infection of the hepatobiliary system and small intestine. The organisms
were readily identified in the bile ducts and gall bladder by special
stains and by in situ hybridization using a probe directed against the
small subunit ribosomal RNA of human origin E. bieneusi. Infection of
the biliary system was associated with a nonsuppurative and
proliferative cholecystitis and choledochitis. Hepatic involvement was
characterized by bridging portal fibrosis and nodular hepatocellular
regeneration accompanied by marked bile ductular and septal duct
hyperplasia. Ultrastructurally, all developmental stages of the organism
were found in direct contact with the host cell cytoplasm; spores and
sporoblasts contained a double layer of polar tubes. Sequencing of a
607-bp segment of the small subunit ribosomal RNA revealed 97 and 100%
identity to two clones of small subunit ribosomal RNA derived from E.
bieneusi of human origin. Extensive morphological and genetic
similarities between the simian and human enterocytozoons suggest that
experimentally infected macaques may serve as a useful model of
microsporidial infection in AIDS.
*Biliary Tract Diseases/PATHOLOGY *Liver Diseases/PATHOLOGY
*Microspora Infections/PATHOLOGY *Microsporida/ISOLATION & PURIF
*Opportunistic Infections/PATHOLOGY *Simian Acquired Immunodeficiency
Syndrome/PATHOLOGY