Available data is too limited to affirm that residence or travel in tropical countries increases the risk for microsporidial infection, but the cases presented here suggest that E. bieneusi could be a cause of self-limited diarrhea in immunocompetent travelers returning from the tropics or could chronically affect immunocompromised HIV-infected travelers.
In this report we describe the cultivation of two isolates of microsporidia, one from urine and the other from sputum samples from a Spanish AIDS patient. We identified them as Encephalitozoon cuniculi, type strain III (the dog genotype), based on ultrastructure, antigenic characteristics, PCR, and the sequence of the ribosomal DNA internal transcribed spacer region.Encephalitozoon cuniculi is known to infect different tissues, including the urinary system and the central nervous system (CNS), of laboratory animals and cause widespread disease (2). Reports of CNS infection in immunocompetent humans thought to be caused by E. cuniculi have also been decribed for a Japanese boy (17) and a Swedish child (1) as well as for the liver (22) and peritoneum (30) of AIDS patients. Further, recent studies based on in vitro culture and molecular and antigenic characterization of several isolates (3, 6, 8, 9, 11, 13-16, 18, 20, 28) have identified E. cuniculi as an agent of respiratory, urinary, and CNS infections in AIDS patients. We describe here the isolation, in vitro cultivation, and ultrastructural, antigenic, and molecular characterization of E. cuniculi isolated from the sputum and urine of a Spanish patient with AIDS. CASE REPORTA 35-year-old Spanish injection drug user known to be HIV positive since 1985 was admitted to the Ramon y Cajal Hospital in Madrid (Spain) in August 1992 because of an 8-month history of fever, progressive weight loss (10 kg), asthenia, epigastric abdominal pain, and diarrhea. He had a CD4 count of 34/mm 3 and was negative for toxoplasmosis, leishmaniasis, cryptococcosis, brucellosis, tuberculosis, and Mycobacterium avium complex and other pathogenic bacteria. Biopsies of bone marrow, stomach, and duodenum as well as feces were negative for parasites (including Cryptosporidium but not microsporidia), fungi, and bacteria, although he was culture positive for cytomegalovirus (CMV). The patient was enrolled in a prospective study of human microsporidiosis. Smears made from seven stool samples obtained during a period of 10 months, sputum, and two urine samples when stained with modified trichrome (26) revealed microsporidial spores. Although the patient was treated for multiple opportunistic infections, his condition deteriorated gradually, resulting in his death. MATERIALS AND METHODSIn vitro culture, electron microscopy, and serologic and molecular studies. Urine and sputum samples were processed for culture as described previously (24), and the resultant cultures were designated USP-A1 (established from the urine sample) and USP-A2 (resulting from the sputum sample). Reference strains Encephalitozoon intestinalis CDC:V297 (23), Encephalitozoon hellem CDC:V213 (25), and E. cuniculi CDC:V282 (6) were also cultured. Spores from test isolates and from the reference strains were harvested periodically, pooled, and purified separately as described before (7). Smears of culture-derived spores were also stained with either the Gram chromotrope technique (19) or with Calcofluor white reagent (10). ...
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.
A prospective study was carried out to determine the prevalence rates of microsporidiosis and other enteroparasites in HIV-positive children in the Madrid area. HIV-positive pediatric patients from three hospitals were enrolled in the study. A total of 293 samples (158 stool and 127 urine) were collected from 83 children whose mean age was 6.3 years and had a mean CD4 count of 504.7/mm3 (range 1-2,220/mm3), 48 of whom suffered diarrhea at the time of the study. Microsporidia identification was investigated in stool and urine samples using Weber's chromotrope-based stain, IIF and PCR species-specific tests. Enteric parasites were identified in 32.5% of the children. Cryptosporidium sp. was the most common parasite encountered (14.4%), followed by Blastocytis sp. (9.6%) and Giardia duodenalis (8.4%). Microsporidia was only found in the stools of one child (1.2% of total and 2% of those with diarrhea) and Enterocytozoon bieneusi was demonstrated by PCR. The patient was 10 years old, presented non-chronic diarrhea and his CD4 count was 298/mm3. These data differ from those previously reported by us in HIV-positive adults (13.9%) in the same area, although this group showed more severely depressed CD4 lymphocyte counts than children. New epidemiological studies should be carried out to elucidate whether additional risk factors exist between these groups.
Intestinal microsporidiosis has been associated traditionally with severely immunocompromised patients with AIDS. We describe two new cases of intestinal microsporidiosis due to Enterocytozoon bieneusi in human immunodeficiency virus -negative adults. Both patients presented with chronic nonbloody diarrhea, and one had intestinal lymphangiectasia as well. Intestinal microsporidiosis was diagnosed by evaluation of stool samples, and the specific species was determined by use of polymerase chain reaction (PCR) in duodenal biopsy specimens. To our knowledge, this is the first report of confirmation of E. bieneusi in the intestinal epithelium of HIV-negative individuals by use of PCR in duodenal biopsy specimens. Cases of intestinal microsporidiosis in HIV-negative individuals reported in the English-language literature are reviewed. These two new cases along with those described previously corroborate the need to evaluate for microsporidia in HIV-negative individuals with unexplained diarrhea.Several clinicoepidemiological studies have shown that Enlast 20 years. In 1991, intestinal lymphangiectasia, a generalized congenital disorder of the lymphatic system that originates terocytozoon bieneusi is the intestinal microsporidian encountered most frequently in patients with AIDS [1 -3]. In addition, in an immunodeficient setting, was diagnosed. In 1996 he was admitted to the hospital for evaluation of diarrhea, three loose the organism is becoming increasingly common in immunocompetent individuals [2]. To date, there are reports of only bowel movements per day, and a 6-month history of right pretibial edema. Laboratory studies revealed the following valnine children [4, 5] and five adults [6 -10], all HIV-negative, who have had intestinal microsporidiosis diagnosed, and ues: lymphocyte count, 0.8 1 10 9 /L; CD4 cell count, 0.32 1 10 9 /L; CD8 cell count, 0.12 1 10 9 /L; CD4-CD8 ratio, 2.6; total E. bieneusi was identified in stool samples from 11 of them; species-level identification was not attained for the other three protein level, 40 g/L; IgG level, 1.3 mg/mL; IgA level, 0.71 mg/mL; and IgM level, 0.17 mg/mL. Delayed-type hypersensipatients [4, 8]. We report two new cases of intestinal microsporidiosis due to E. bieneusi in HIV-negative adults from Vitoria tivity skin tests showed normal responses. Serologies for antibodies to HIV-1 and HIV-2 were negative. Results of the Van (Alava, Spain), identified in stool samples as well as duodenal biopsy specimens. To our knowledge, these are the first cases de Kamer, Schilling, and D-xylose tests were indicative of intestinal malabsorption. Esophagogastroduodenoscopy of confirmation of E. bieneusi by use of PCR in the duodenal biopsy specimens of HIV-negative individuals with intestinal showed edematous folds and nonoverelevated erythematous symptoms.lesions in the third duodenal portion. Repeated routine stool cultures for detection of pathogenic bacteria (including mycobacteria) and ova and parasites and a specific Case Reports monoclonal antibody test for Cryptosporid...
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