TY - CHAP M1 - Book, Section TI - Chapter 347. Dientamoebiasis A1 - Murray, Dennis L. A2 - Rudolph, Colin D. A2 - Rudolph, Abraham M. A2 - Lister, George E. A2 - First, Lewis R. A2 - Gershon, Anne A. PY - 2011 T2 - Rudolph's Pediatrics, 22e AB - Dientamoeba fragilis is a nonflagellate trichomonad parasite that inhabits the human colon and has been associated with acute and chronic gastrointestinal symptoms. Humans are likely the natural host for D fragilis. Unlike most other intestinal protozoa, D fragilis has no known cyst form and has not been found to invade tissues.1 The organism is usually 7 to 12 μm in diameter and demonstrates pointed or leaf-shaped pseudopodia (see Fig. 347-1). While moving actively in fresh fecal specimens, the organism quickly becomes rounded and granular and is therefore less identifiable in stored specimens. When suitably stained, most D fragilis reveal two characteristic nuclei that each contains a large karysome with granules. Some large uninucleate forms may also be found. The organism feeds on bacteria and will ingest human red blood cells.1 Advances in culturing techniques have improved the ability to detect the organism2-4 but are limited, since cultures cannot be done on fixed fecal samples. Because of its small size, this organism may be overlooked by inexperienced laboratory personnel or can be lost if not preserved properly. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/04/19 UR - accesspediatrics.mhmedical.com/content.aspx?aid=7031685 ER -