Medical Microbiology Lab 2: Protozoa PDF

Al-Maaqal University Collage of Pharmacy Medical Microbiology 2nd Stage LAB 2 protozoa (Plasmodium falciparum , Trypanosoma brucie , Giardia lamblia) Prepared By Masarra Adnan Shakir Plasmodium spp. Plasmodium is a member of the phylum Apicomplexa a large group of...

Al-Maaqal University Collage of Pharmacy Medical Microbiology 2nd Stage LAB 2 protozoa (Plasmodium falciparum , Trypanosoma brucie , Giardia lamblia) Prepared By Masarra Adnan Shakir Plasmodium spp. Plasmodium is a member of the phylum Apicomplexa a large group of parasitic eukaryotes. within Apicomplexa Plasmodium is in the order Haemosporida and family Plasmodiidae. There are several species of Plasmodium but only four species can infect humans 1.Plasmodium vivax 2.Plasmodium ovale 3.Plasmodium malariae 4.Plasmodium falciparum Plasmodium spp. Habitat In human, the parasites are found in the erythrocytes and hepatocytes. Vectors Human malaria is transmitted by over 60 species of female Anopheles mosquito.  What causes malaria? Malaria is spread when an infected Anopheles mosquito bites a person. You can't get malaria just by being near a person who has the disease. Anopheles is the only type of mosquito that can spread malaria, It becomes infected by biting an infected person and drawing blood that contains the parasite.. Morphology of Plasmodium spp. Plasmodium spp. appear in several stages:- Sporozoites Schizont Trophozoite Merozoites Morphology of Plasmodium spp Ring stage: Ookinate Microgamete Macrogamete Oocyst  Plasmodium falciparum Its cause disease called as malignant tertian, subtertian malaria, consider the most virulent of Plasmodium spp. in human. Falciparum malaria is potentially life- threatening. Patients with severe falciparum malaria may develop liver and kidney failure, convulsions, and coma. Laboratory Diagnosis 1. Microscopic examination (Gold standard) Demonstration of malarial parasite in the peripheral blood in thin and thick smears: Thin smear is used for detecting the parasites and determining the species by studying its morphological details. The thick smear is more sensitive and is used for detection of malarial parasite when there is low parasitemia. Laboratory Diagnosis Rings, About 1/5 Rings, About 1/5 Microgametocyte diameter of RBC diameter of RBC Sausage or banana- chromatin small chromatin two shaped pale blue or dots, two dots dots frequent pink cytoplasm large frequent diffuse nucleus Macrogametocyte Schizont 8-24 merozoite Laboratory Diagnosis 2. Rapid diagnostic tests (RDT) The tests aid in the diagnosis of malaria by detecting malaria parasite antigens in human blood. 3. Molecular diagnosis PCR on blood. Trypanosoma spp. Trypanosomes are unicellular organisms with the ability to move freely. In one of their life forms they live within the blood stream and tissues of the human and other animals. The organisms live part of their life cycle within an insect host Morphology Form of Trypanosoma spp. 1-Amastigote 2-Promastigote 3- Epimastigotes 4-Trypomastigote Trypanosoma spp There are three species in genus Trypanosoma which infect only human Trypanosoma brucie gambiense  West-African sleeping sickness  Gambian trypanosomiasis, Trypanosoma brucie rhodesiense  East-African sleeping sickness  Rhodesian trypanosomiasis, Trypanosoma cruzi  Chagas disease  American Trypanosomiasis Trypanosoma brucie gambiense Trypanosoma brucie rhodesiense  The parasite exists in two forms , trypomastigotes and epimastigotes  The insect Glossina palpalis (tse tse fly) is the vector host.  Trypomastigotes are seen in the vertebrates (human) as well as in the insect host Mode of infection The insect inject metacyclic trypomastigotes in the blood of human when feeding on his blood. Laboratory diagnosis 1-Clinical diagnosis Enlarging lymph nodes behind the neck and other neurological symptoms 2-Microscopic examination Wet mount preparation of lymph node aspirates, CSF, and chancre fluid are used for demonstration of trypomastigotes. These specimens can be fixed and stained with Giemsa. 3.-Culture Culture is not routinely used. 4-Serodiagnosis Specific antibodies or antigens can be detected in serum and CSF. 5.-Molecular diagnosis PCR on clinical specimens. Laboratory diagnosis Trypomastigote is infective and diagnosis stage Trypanosoma spp. Giardia lamblia Giardia lamblia is a flagellate of world-wide distribution. Its causing dieses called Giardiasis. Habitat Giardia lamblia lives in the duodenum and upper jejunum. Mode of transmission by ingestion of cysts through contaminated food and water. Giardia lamblia Trophozoites:- Have two nuclei, two axostyles, two basal body, and 8 flagella. Its looking – like tennis rackets without the handle (it seem like comical face when looking at the front view). Giardia lamblia Cysts:- Have 4 nuclei clustered on one end, and longitudinal fibrils consisting of the remains of axostyles and basal bodies. Giardia lamblia  Laboratory Diagnosis Finding the characteristic cysts in normal stool by examination of the deposit of a formol-ether concentrate of stool preparation Detecting the characteristic trophozoites in a wet preparation of diarrheic. Both cysts and trophozoites can be found in the feces (diagnostic stages), cysts (infective stage)