Taxonomy: f. Monoceromonadidae
Animal: Dientamoeba fragilis 5 10.jpg
Dientamoeba fragilis trophozoite 5 - 15 microns (average 9 - 12) with 1 or 2 nuclei with no peripheral chromatin and a karysome made of a cluster of 4 - 8 granules in faecal smear stained with Trichrome. A minimum of 3 specimens should be submitted for the diagnosis of Dientamoeba infections. A permanent stain is essential as these delicate organisms can be easily missed although if the specimen is very fresh, they can be seen moving in a non-progressive way with their pseudopods in a saline preparation but no morphological details necessary for a definitive diagnosis can be seen. . I (R. Pugh) found that having the faecal specimen fixed as soon as possible after excretion improves the ability to detect these delicate parasites; there is no cyst stage. Examining either the Trichrome or FeHx stained smear using x100 magnification carefully is mandatory to detect these organisms. These parasites are therefore probably under-reported and are understudied. Pathogenicity is not well defined, it has been reported to be associated with a range of gastro-intestinal symptoms and this specimen was from an adult female with severe, intermittent diarrhoea.
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