Detection of Enterocytozoon bieneusi (Microsporidia) by polymerase chain reaction (PCR) using species-specific primer in stool samples of HIV patients.

BACKGROUND & OBJECTIVE: Microsporidia are obligate intracellular parasites causing infections predominantly in immunocompromised patients. Enterocytozoon bieneusi is the most important microsporidian causing chronic diarrhoea in AIDS patients. The current method used for diagnosing the microsporidia spores is based on light microscopy using stained smears, which do not differentiate spores at species level. The present study was undertaken to detect microsporidia and confirm at species level (E. bieneusi) by PCR from stool samples of HIV positive patients. METHODS: During September 2002 to April 2003, stool samples from 153 HIV-positive patients (with chronic diarrhoea n = 105; without diarrhoea n=48) were collected and examined microscopically for microsporidia spores using modified Weber's chromotrope stain. Stool samples were subjected to PCR assay using species-specific primer EBIEFI/EBIER1, which amplifies small subunit ribosomal RNA (SSU rRNA) of this microsporidian RESULTS: A total of 10 HIV positive patients with chronic diarrhoea were positive for microsporidia by microscopic analysis and confirmed as Enterocytozoon bieneusi by PCR. No false positive results were observed. A diagnostic DNA fragment of 607 bp of the unique SSU rRNA was amplified from all samples infected with E. bieneusi. INTERPRETATION & CONCLUSION: The study revealed that polymerase chain reaction is a useful tool for accurate species identification of microsporidia in stool samples, which serves the benefit of treatment to the patients.

Role of coccidian parasites in causation of diarrhoea in HIV infected patients in Chennai.

BACKGROUND & OBJECTIVES: Diarrhoea is one of the major problems of HIV positive patients. A coproparasitological study was carried out to assess the role of coccidian parasites in the causation of diarrhoea in HIV infected patients in Chennai. METHODS: During May 2000 to January 2001, 152 stool samples from HIV seropositive individuals (43 with acute diarrhoea, 59 with chronic diarrhoea, 50 without diarrhoea) and 50 normal individuals without diarrhoea were examined for enteric coccidian and other intestinal parasites by microscopy and special staining methods. RESULTS: A total of 52 enteric parasites, 15 from patients with acute diarrhoea and 24 from patients with chronic diarrhoea, 7 from patients infected with HIV without diarrhoea and 6 from normal individuals without diarrhoea were detected from 49 patients. Isospora belli was detected in 14 of 102 (13.7%) patients with acute and chronic diarrhoea. The association with diarrhoea among HIV positive individuals was significant (P < 0.001). Cryptosporidium was detected in 7 patients each with acute and chronic diarrhoea and 4 patients with HIV infection without diarrhoea, its association with diarrhoea among HIV patients was found to be not significant in the present study. Cyclospora and Microsporidia each were detected in only one HIV positive patient with chronic diarrhoea. INTERPRETATION & CONCLUSION: The study revealed that the coccidian parasites are one of the important etiologic agents of diarrhoea (P < 0.001) especially of chronic diarrhoea among HIV positive patients. Isospora belli was found to be a frequent enteric parasite associated with diarrhoea among HIV positive patients in Chennai.