Detection of Microsporidia by different staining techniques.

Previous detection of Microsporidia relied mainly on electron microscopy and histopathology. Recently, non invasive methods were able to recognize this microorganism. In the present study, different stains were used as a means of diagnosing spores of Microsporidia in stool samples of immunosuppressed patients. The original modified trichrome stain (MTS) was used as a standard screening technique for all stool samples. Positive samples for Microsporidia were then stained with the trichrome blue stain, Didier's trichrome blue stain, acid-fast trichrome stain (AFT), modified Ziehl-Neelsen stain, giemsa stain and calcofluor white M2R stain. Both calcofluor and the AFT stains were most efficient. They could simultaneously detect coccidial oocysts and microsporidial spores. This is beneficial and time-saving in the diagnosis of stool samples of immunosuppressed patients, which usually contain more than one opportunistic protozoon. Both stains are easy to perform and require the least amount of staining and examination.