Department of Medicine, Division of Infectious Diseases, Department of Pathology, Division of Parasitology and Tropical Medicine, Department of Animal Medicine, Department of Medicine, Division of Gastroenterology, Albert Einstein College of Medicine, Department of Biological Sciences, Rutgers University, Bronx, New York
Microsporidia are very primitive, eukaryotic, obligate, intracellular, protozoan parasites. Encephalitozoon cuniculi, a microsporidian originally described from a rabbit infection, has been described in humans as well as in many species of laboratory animals. We report the detection of E. cuniculi by Western blotting in a rabbit with torticollis that was obtained from an Encephalitozoon-free colony. Cross-reactivity of this serum was observed with antigens prepared from several genera of microsporidia. Identical Western blotting patterns were obtained with sera obtained from a rabbit immunized with E. cuniculi that was purified from tissue culture cells. In addition, we were able to demonstrate cross-reactivity between E. cuniculi rabbit antisera and Enterocytozoon bieneusi antigens by indirect immunofluorescent assay techniques in human intestinal biopsy samples. These cross-reactions between microsporidia may be useful in developing diagnostic tests for non-cultivatable microsporidia such as Enterocytozoon bieneusi.