Protozoa Definition: Number: Size: Form : ectoplasm(gel state) cytoplasm endoplasm(sol state) Body of protozoa: protoplasm nucleoplasm
Nucleus: reproduction Containing chromosomes: transmission of genes Type of nucleus: 1- vesicular n. 2- compact or graular n. 3- bi-nuclated: similar: dissimilar n. : macro & micronucleus 4- multi-nuclated:
Ectoplasm Function Endoplasm Function Protection of the organism Locomotor apparatus Food ingestion Respiration Discharge of metabolic wastes containing ; mitochondria,golgi,... Food synthesis Glycogen vacuoles & chromatidal bodies Food vacuoles Excretory vacuoles(collection of fluid wastes) Contractive vacuoles(maintain osmotic pressure)
Parasitic Amebae Characters of the genus Entamoeba : - possession a vesicular nucleus -small karyosome located at or near center of nucleus Varying number of peripheral chromatin granules attached to the nuclear membrane
Entamoeba gingivalis (non-pathogen) - Prevalance rate: … to 90% of dental patient 10% of person with good oral hygiene Live site Morphology Diagnosis : may be mistaken for E.histolytica from a pulmonary abscess
Entamoeba hartmani *small race of E.histolytica (morphologic similarity) *only clear-cut distinction between the two species is size *tr0phozoite ingest bacteria but no RBC *size: trophozoite < 12 mμ, c yst < 10 mμ
Entamoeba dispare : *There is no morphologic differences between this amoeba with E.histolytica *This amoeba no ingest RBC Iodamoeba butschlii : * Trophozoite size(4-20 μm ) *Cyst size(9-10 μm )
Endolimax nana * most common of the smaller intestinal amaeba *Size *Motility movement *Cytoplasm *Cyst:
Free-Living Amebae (Opp0rtuistic Amebae) Family: Vahlkampfiidae Acathamoebidae Leptomyxidae Genus: Naegleria Acanthamoeba Balamuthia Genus: Naegleria Acanthamoeba Balamuthia Species: fowleri castellani mandrillaris gruberie calbertsoni gruberie calbertsoni aerobia polyphaga aerobia 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, in motion; is elongate, broad anteriorly, distinctly tapered posteriorly, forms a single pseudopod, dimensions 7 by 20 μm With a nucleus contain a large central karyosome *Flagellate form: with two flagella, pear-shaped, do not divided *Cyst form: uninucleate, circular 7-10 μm in diameter, nucleus is similar to troph.
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
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
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. *is made by microscopic identification of living or Wright-stained amebae in the patient’s CSF or trophozoites and cysts of Acanth. In brain tisse. * 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.
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