DIAGNOSIS OF INFECTIONS CAUSED BY ENTEROCYTOZOON-BIENEUSI AND ENCEPHALITOZOON INTESTINALIS USING POLYMERASE CHAIN-REACTION IN STOOL SPECIMENS

Objective: To study the usefulness of polymerase chain reaction (PCR) for the species identification of microsporidia in stool specimens obt ained from HIV-infected patients with Enterocytozoon bieneusi or Encep halitozoon intestinalis infections. Setting: Infectious disease clinic in a university hospital. Patients: Thirty-seven stool specimens from 29 HIV-infected patients with microsporidiosis were tested. The diagn osis of microsporidian infection was made by light microscopy of stool specimens and species identification was made by transmission electro n microscopy of duodenal biopsies. Sixty-one stool specimens from 45 H IV-infected patients without microsporidiosis sewed as controls. Metho ds: PCR was performed using DNA extracted from stools with two primers sets, one specific for E. bieneusi and one specific for E. intestinal is. Results: A 1265 base-pair fragment of the small subunit ribosomal RNA (rrs) gene could be amplified from all 31 stool specimens infected with E. bieneusi. In addition, a 930 base-pair fragment of the rrs ge ne could be amplified from all six stool specimens infected with E. in testinalis. The 61 control stools were negative with both primers. Con clusions: These results suggest that a PCR-based assay using species-s pecific primers sets can be used successfully for microsporidian speci es differentiation from stool specimens, thus obviating the need for i nvasive biopsy procedures.