POLYMERASE CHAIN-REACTION FOR MICROSPORIDIAN DNA IN GASTROINTESTINAL BIOPSY SPECIMENS OF HIV-INFECTED PATIENTS

Objective: To study the accuracy of polymerase chain reaction (PCR) fo r microsporidian DNA in gastrointestinal biopsy specimens of HIV-infec ted patients for the diagnosis of intestinal microsporidiosis. Setting : infectious disease in- and outpatient clinic of a university hospita l in Cologne, Germany. Patients: Forty-six HIV-infected patients with diarrhoea. Methods: PCR and Southern blot hybridization were performed using DNA extracted from intestinal biopsy specimens with primers and probes from the small subunit rRNA gene of Enterocytozoon bieneusi an d Septata intestinalis. Histological examination of intestinal biopsy specimens was performed using a fluorescence technique. Transmission e lectron microscopy of intestinal biopsy specimens was performed in 13 patients. Results: Amplification and Southern blot hybridization with species-specific primers and probes gave positive results in 10 patien ts for E. bieneusi, and in 10 patients for S. intestinalis. Overall, f ive cases of double infection with E, bieneusi and S. intestinalis wer e seen when both primer pairs and probes were used. Histological exami nation showed microsporidian spores in all 15 cases, but light microsc opy was unable to distinguish between species in almost all cases. Con clusions: PCR detection of microsporidian DNA in intestinal biopsy spe cimens can be used reliably for the diagnosis of intestinal microspori diosis in HIV-infected patients and is also useful for species differe ntiation between microsporidia. Infections with S. intestinalis and do uble infections with two types of microsporidia appear to be more comm on than previously described.