In situ hybridization: A molecular approach for the diagnosis of the microsporidian parasite Enterocytozoon bieneusi

Microsporidia are emerging as opportunistic pathogens in patients with acqu ired immunodeficiency syndrome (AIDS), Enterocytozoon bieneusi is the most commonly reported microsporidium that is detected in gastrointestinal speci mens. This report describes an in situ hybridization technique with a 30-ba se specific synthetic DNA probe for detection of E. bieneusi by light micro scopy. Formalin-fixed paraffin-embedded duodenal biopsy specimens from thre e patients with IUDS, chronic diarrhea, and E bieneusi infection confirmed by electron microscopy were used in this study. Light microscopic examinati on after colorimetric detection allowed the identification of different sta ges of the pathogen's life cycle in the cytoplasm of enterocytes. No cross- reactivity was noted between the probe and human DNA. Our study underscores : the applicability of a synthetic-labeled oligonucleotide for the detectio n and identification of E bieneusi in clinical samples. HUM PATHOL 30:54-58 . Copyright (C) 1999 by W.B. Saunders Company.