Development of a real-time polymerase-chain-reaction assay for quantitative detection of Enterocytozoon bieneusi DNA in stool specimens from immunocompromised patients with intestinal microsporidiosis

J Infect Dis. 2003 May 1;187(9):1469-74. doi: 10.1086/374620. Epub 2003 Apr 15.


A new real-time polymerase chain reaction (PCR) method was developed for quantitation of Enterocytozoon bieneusi DNA in sequential stool specimens from immunocompromised patients with intestinal microsporidiosis. Patients were treated with fumagillin (n=6) or with placebo (n=6), in a randomized comparative trial. At baseline, mean E. bieneusi DNA levels were not significantly different in stool specimens from the placebo group, compared with those from the fumagillin group (5.9+/-0.4 vs. 5.9+/-0.6 log(10) copies/microL of stool suspension, respectively; P=.96). In the placebo group, parasitic burden remained stable during follow-up (P=.46), whereas, in the fumagillin group, E. bieneusi DNA levels dropped below the lower limit of detection in all patients (mean reduction from baseline, -4.7 log(10) copies; P<.0001). Real-time PCR performed better than did semiquantitative assessments by microscopy, to measure parasitic burden. In conclusion, this real-time PCR assay is a reliable tool for quantitation of E. bieneusi DNA in stool specimens and for the monitoring of treatment efficacy.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antiprotozoal Agents / therapeutic use
  • Cyclohexanes
  • DNA, Protozoan / analysis*
  • DNA, Protozoan / genetics
  • Enterocytozoon / genetics*
  • Enterocytozoon / isolation & purification*
  • Fatty Acids, Unsaturated / therapeutic use
  • Feces / parasitology*
  • Humans
  • Immunocompromised Host*
  • Intestinal Diseases, Parasitic / diagnosis
  • Intestinal Diseases, Parasitic / drug therapy
  • Intestinal Diseases, Parasitic / parasitology
  • Microsporidiosis / diagnosis*
  • Microsporidiosis / drug therapy
  • Microsporidiosis / parasitology
  • Polymerase Chain Reaction / methods*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Sesquiterpenes


  • Antiprotozoal Agents
  • Cyclohexanes
  • DNA, Protozoan
  • Fatty Acids, Unsaturated
  • Sesquiterpenes
  • fumagillin