Identification of Enterocytozoon bieneusi spores in respiratory samples from an AIDS patient with a 2-year history of intestinal microsporidiosis.

Enterocytozoon bieneusi, a microsporidian parasite, has been recognized since 1985 as an agent of intestinal microsporidiosis leading to malabsorption syndrome, diarrhea, and weight loss in AIDS patients. Recently, however, we have identified E. bieneusi spores in the sputum, bronchoalveolar lavage, and stool samples of an AIDS patient with a 2-year history of intestinal microsporidiosis. The spores were characterized by Weber's chromotrope-based staining, immunofluorescence tests, and PCR. No microsporidia were detected in urine samples by the same techniques. PCR was performed with DNAs purified from specimens with E. bieneusi-, Encephalitozoon cuniculi-, Encephalitozoon hellem-, and Encephalitozoon (Septata) intestinalis-specific primers. Treatment with albendazole and loperamide resulted in an improvement of intestinal symptoms, without eradication of the parasite. To our knowledge, this is the second report of the identification of E. bieneusi spores in respiratory and enteric samples obtained from an AIDS patient. Although no pulmonary pathology could be established in either of these cases, it is now clear that E. bieneusi is capable of colonizing the respiratory tract and it is suggested that investigators should be aware of the possibility of finding E. bieneusi spores in respiratory secretions.