بسم الله الرحمن الرحیم

Kingdom protista (classification of protozoa) Subk.: Protozoa phylum: Apicomplexa Ciliophora Sarcomstigophora Microspora Subph: Sarcodina Mastigophora (Amebae) (Flagellates) Parasitic Amebae Free-living Amebae Family: Endamoebidae Leptomyxidae Acanthamoebidae Vahlkampfidae Genus: Entamoeba Iodamoeba Endolimax gingivalis butschlii nana Sp. Hartmani histolytica coli dispare

Entamoeba gingivalis (non-pathogen) -Prevalance rate - Live site - Morphology - cytoplasm Diagnosis: may be mistaken for E.histolytica from a pulmonary abscess

Entamoeba coli (non-pathogen) Prevalance: 1 to 50% Morphology: trophozoite range 15-50µm ( very closely resemble E.histolytica) - cytoplasm - Pseudopodia Motility *nucleus *karyosome *peripheral chromatin

Entamoeba hartmani *small race of E.histolytica (morphologic similarity) *size: trophozoite < 12 mμ , c yst < 10 mμ *only clear-cut distinction between the two species is size *trophozoite ingest bacteria but no RBC

Entamoeba dispare : Iodamoeba butschlii : *There is no morphologic differences between this amoeba with E.histolytica *This amoeba no ingest RBC Iodamoeba butschlii : *Trophozoite size(4-20μm), cytoplasm may be contain bacteria, large karyosome, small granules *Cyst size(9-10 μm): contain glycogen vacuole, sigle nuclei

Endolimax nana *most common of the smaller intestinal amaeba *Size: trophpozoite and cyst is similar to theat of E.hartmani *Motility: sluggish pseudopodia extruded rapidly *Cytoplasm: Nucleus: contain large karyosome *Cyst:

Free-Living Amebae (Opp0rtuistic Amebae) Family: Vahlkampfiidae Acathamoebidae Leptomyxidae Genus: Naegleria Acanthamoeba Balamuthia Species: fowleri castellani mandrillaris calbertsoni polyphaga Habitat: in fresh, brackish and salt water, moist soil and decaying vegetation History: Human infection were first reported by Fowler in 1965 Geographic distribution: The most cases were reported from; USA, Australia, Czech, Oslovakia, Belgium, India,…….. Epidemiology: Most cases have occurred during summer in young persons who swam or dived in swimming pools and during the ritual washing before prayer

Naegleria fowleri Morphology , Biology and Life cycle: flagellate form *Life cycle stage consist: -motile trophozoite: -nonmotile cysts ameboid form *Reproduction: simple binary fission *Ameboid form: found in tissue , forms a single pseudopod, dimensions 7 by 20μm, With a nucleus contain a large central karyosome *Flagellate form: with two flagella, pear-shaped, do not divided *Cyst form: uninucleate, circular 7-10μm in diameter, nucleus is similar to troph.

Naegleria forms

Naegleria cyst & trophozoite

Life cycle

Symptoms and pathogeesis Primary Amebic Meningoencephalitis(P.A.M.) : Symptoms; headache, fever, nausea and vomiting accompanied by signs of meningitis with involvement of the olfactory, frontal, temporal, and cerebral areas Death : occurs early; the entire clinical course seldom extends beyond 3 to 6 days.

Acanthamoeba( Hartmanella) spp. Morhology, Biology and Life cycle: These amebae are similar in appearance to the ameboid stage of Naegleria but have no flagellate stage. Cyst & Trophozoite may be found in tissue, but cysts are never seen in Naegleria infections. Pseudopods are acanth forms

Acanthamoeba trophozoite

Free-living Amebae Life Cycle

Symptoms & Pathogenesis Granulomatous Amebic Encephalitis( GAE): *Invasion of the CNS is not associated with swimming but is secondary to infection elsewhere in the body . Amebae reach the brain by way of blood stream, likely from lung or through ulcer the skin or mucosa Occurs most often in debilitated or immunocompromised persons A. astronyxis and A. palestinensis associated only with CNS infection Acanthamoeba Keratitis: * Affects healthy person, increase in the number of cases in the recent years has been linked to the wearing of contact lenses, especially soft ones. A. polyphaga and A.hatchetti only with eye infection. Chronic granulomatous infection of the skin A. castellani, A. culbertsoni ,….. Have causea both CNS and eye infections

Keratitis

Diagnosis of PAM and GAE: Diagnosis of PAM and GAE: *A patient’s history of having been swimming in water 3 to 6 days prior to onset of symptoms of PAM suggest a possible diagnosis. * In brain tisse is made by microscopic identification of living or Wright-stained amebae in the patient’s CSF or trophozoites and cysts of Acanth.. * by cultivation of cerebrospinal fluid in medium non-nutrient agar seeded with living Escherichia coli for PAM and corneal scraping cultured for Acanth. Keratitis. Treatment: At present there is no satisfactory treatment fir PAM and GAE. *Amphotericin B, is administered intravenously in large doses; 1 to 1.5 mģ/kg body weight daily for 3 days, followed by 1 mg/kg daily for 6 days. *Miconazole and Rifampin are other alternative drugs.