SPECIES-SPECIFIC IDENTIFICATION OF MICROSPORIDIA IN STOOL AND INTESTINAL BIOPSY SPECIMENS BY THE POLYMERASE CHAIN-REACTION

In view of the increasing number of cases of human microsporidiosis, s imple and rapid methods for clear identification of microsporidian par asites to the species level are required, in the present study, the po lymerase chain reaction (PCR) was used for species-specific detection of Encephalitozoon cuniculi, Encephalitozoon hellem, Encephalitozoon ( Septata) intestinalis, and Enterocytozoon bieneusi in both tissue and stool. Using stool specimens and intestinal biopsies of patients infec ted with Enterocytozoon bieneusi (n = 9), Encephalitozoon spp. (n = 2) , and Encephalitozoon intestinalis (n = 1) as well as stool spiked wit h spores of Encephalitozoon cuniculi and Encephalitozoon hellem and ti ssue cultures of Encephalitozoon cuniculi and Encephalitozoon hellem, three procedures were developed to produce PCR-ready DNA directly from the samples. Specific detection of microsporidian pathogens was achie ved in the first PCR, The subsequent nested PCR permitted species dete rmination and verified the first PCR products. Without exception, the PCR assay confirmed electron microscopic detection of Enterocytozoon b ieneusi and Encephalitozoon intestinalis in stool specimens and their corresponding biopsies and in spiked stool samples and tissue cultures infected with Encephalitozoon cuniculi and Encephalitozoon hellem. Mo reover, identification of Encephalitozoon spp. could be specified as E ncephalitozoon intestinalis. Whereas standard methods such as light an d transmission electron microscopy may lack sensitivity or require mor e time and special equipment, the PCR procedure described facilitates species-specific identification of microsporidian parasites in stool, biopsies, and, probably, other samples in about five hours.