Basic and Laboratory Parasitology (HLPR-301) Fall 2024-2025 PDF

Basic and laboratory parasitology Faculty of Applied Health Sciences Technology (HLPR-301) Fall 2024-2025 Protozoa Part I  Welcome!! Protozoa Part I  Protozoa Unicellular microscopic organisms  General characteristics of Protozoa : ❖ Protozoa are unicellular microscopic o...

Basic and laboratory parasitology Faculty of Applied Health Sciences Technology (HLPR-301) Fall 2024-2025 Protozoa Part I  Welcome!! Protozoa Part I  Protozoa Unicellular microscopic organisms  General characteristics of Protozoa : ❖ Protozoa are unicellular microscopic organisms, ranging in size from 2 to more than 100um. ❖ Protozoa are found in all moist habitats. They are common in sea, in soil and in fresh water. ❖ Protozoa multiply by asexual reproduction. ❖ In most parasitic protozoa, the developmental stages are often transmitted from one host to another within a cyst.  General characteristics of Protozoa : ❖ Pathogenic protozoa can spread from one infected person to another by : – Faecal- oral transmission of contaminated foods and water. – Insect bit : inoculum infected insect faeces on the site of bite. – Sexual intercourse.  General characteristics of Protozoa : Ex. Of important pathogenic protozoa causing diseases: ❖ Intestinal tract : Entamoeba histolytica , Giardia lamblia. ❖ Urogenital tract : Trichomonas vaginalis ❖ Blood and tissue : Plasmodium species , Toxoplasma gondii , Trypanosoma, Leishmania. Classification of Protozoa Intestinal Urogenital Blood According to the habitat Intestinal Protozoa Intestinal Protozoa Amoeba Flagellte AMOEBA PATHOGENIC COMMENSAL AMOEBA AMOEBA Is a protozoan parasite that A number of protozoa in the causes disease to the host. It is genus Entamoeba ; worldwide Infectious agent, so it has a distribution and inhabit human capability to invade inside the gastrointestinal tract but are host cells and often referred not believed to cause significant to the: disease and are often referred amphizoic amoeba to the: (due to the ability to exist nonpathogenic ameoba within a host or in the environment as 'free-living’) AMOEBA PATHOGENIC COMMENSAL AMOEBA AMOEBA Entamoeba dispar Entamoeba histolytica Entamoeba hartamani Entamoeba coli Entamoeba moshkovski Endolimax nana Iodamoeba butschlii Entamoeba gingivalis Similarity between the intestinal amoeba : 1 Host : Man. 2 Habitat : Large intestine. 3 Diagnostic stage : Cyst and/or trophozoite. 4 Infective stage : Mature cyst.. 5 Mode of infection : ingestion of cysts in contaminated food, water, or hands. Entamoeba histolytica Trophozoite Size ranges between 20-60 u. Trophozoites move by unidirectional cytoplasmic protrusion. ( The Pseudopodium ) Trophozoites Tissue invading form Trophozoite has clear ectoplasm and granular endoplasm. The nucleus is spherical and contains a small central karyosome. Lining the nuclear membrane are fine regular chromatin granules. E.histolytica Trophozoite E.histolytica Trophozoite E.histolytica Trophozoite Entamoeba histolytica Cyst Size ranges between 10-20 u. They appear as spherical or oval bodies with a hyaline cyst wall. The mature infective cyst: Cyst (The mature four nucleated cyst ) contain four visible nuclei and rod shaped chromatoid body with rounded edges. E.histolytica Cyst E.histolytica Cyst  LIFE CYCLE: The infective stage: The mature 4 nucleated cysts. Mode of infection: ingestion of food or water contaminated with cyst. When cysts are swallowed with food or drink they pass unharmed to the small intestine, where by means of the digestive juices & the alkaline medium, they excyst liberating their content. During excystation, nuclear division is followed by cytoplasmic division giving rise to 8 trophozoites. The released trophozoites migrate to the large intestine. Trophozoites multiply by binary fission & produce cysts which are passed in the faeces. The diagnostic stage: Trophozoites & cysts. E.Histolytica life cycle Thank you