Entamoeba polecki

Morphology, life cycle, diagnosis, symptoms, and treatment.

1. Entamoeba polecki Prepared by: Veronica Baje

2. Entamoeba polecki Entamoeba polecki is an intestinal parasite of the genus Entamoeba. E. polecki is found primarily in pigs and monkeys and is largely considered non-pathogenic in humans, although there have been some reports regarding symptomatic infections of humans

3. Trophozoites Measures 12 to 20 μ m. Trophozoites may vary in size, however, ranging from 8 to 25 μ m. Sluggish, non progressive motility is observed in stools of normal consistency. In diarrheal stools, trophozoites exhibit progressive, unidirectional motility.

4. Cysts Range in size from 10 to 20 μ m, the average is 12 to 18 μ m. Spherical to oval. Contain one nucleus. The nucleus consists of a small central karyosome.

5. Life Cycle There are two stages in the life cycle of E. polecki. The first is as a trophozoite, a vegetative stage that cannot survive in the environment. The second is a cyst, where transmission of parasite is possible and provides protection to harsh external environments. Cysts are infective when ingested by another organism. The cystic form of this protozoan has a diameter as small as 9.5 µm and as large as 17.5 µm. Morphologically, E. polecki is extremely similar to Entamoeba histolytica and Entamoeba hartmanni.

6. Laboratory Diagnosis The trophozoites and cysts of E. polecki may be diagnosed by examining stool samples.

7. Clinical Sympoms Most patients with E. polecki are asymptomatic. The only documented discomfort associated with symptomatic patients is diarrhea.

8. Treatment A combination of metronidazole and diloxanide furoate has successfully treated patients with E. polecki . Metronidazole alone has also been effective.