BMS2037 Protozoa Lecture 2023 PDF

BMS2037 Alison Cottell Protozoa Overview of lecture Principles of protozoan infection Learning outcomes: Identify basic principles of protozoal disease Describe structural features of protozoa, particularly those that influence pathogenesis Appreciate differences in lifecycles of differen...

BMS2037 Alison Cottell Protozoa Overview of lecture Principles of protozoan infection Learning outcomes: Identify basic principles of protozoal disease Describe structural features of protozoa, particularly those that influence pathogenesis Appreciate differences in lifecycles of different pathogenic protozoa, especially through waterborne and vectorborne routes Understand the pathogenesis of human disease caused by the protozoa in the detailed case studies Protozoa: evolution Classification of protozoa: means of movement; nutrition; reproduction Malaria (Plasmodium sp) Apicomplexa Ciliates Paramecium sp. Stentor sp. Toxoplasma gondii Trypanosoma sp. Amoeba sp. Giardia sp. Flagellates Actinophrys sp. Amoebae  General Principles of Protozoan Diseases Transmission via: Ingestion Vectors Sexual contact Giardia lamblia / Transovarial duodenalis / intestinalis Placental Toxoplasma gondii  General Principles of Protozoan Diseases Transmission via: Ingestion Vectors Sexual contact Transovarial Placental Plasmodium sp. Anopheles sp.  General Principles of Protozoan Diseases Transmission via: Ingestion Vectors Sexual contact Transovarial Trichomonas vaginalis Placental Tick: Ixodes scapularis is a Toxoplasmosis gondii Babesia bovis host of B. bovis  Waterborne protozoan diseases Organism Disease Cryptosporidium parvum* Cryptosporidiosis Cyclospora cayetanesis * Cyclosporiasis Giardia lamblia*† Giardiasis †N.B. recently reclassified: Giardia intestinalis and Giardia duodenalis now used Balantidium coli* Balantidiasis (dysentery) Acanthamoeba spp. Keratitis Nagleria fowlerii Brain / CNS disease *These organisms all cause diarrhoeal diseases Red font – reviewed in detail in these lectures  Protozoan disease: arthropod vectors: Insects and ticks Organism Transmission Disease Trypanosoma spp. Tsetse fly Sleeping sickness Triatomine insect Chagas disease Plasmodium spp. Mosquito Malaria Leishmania spp. Sandfly Leishmaniasis Babesia spp. Tick Babesiosis Most vector-borne diseases are viral. Bacteria can also be spread by this route. Lymphatic filariasis: caused by microfilariae (roundworms); mosquito-borne. Cryptosporidium parvum  Cryptosporidiosis – life cycle merozoite clones 6, 7, 8. Further multiplication and release with faeces Genetically 1. Penetrate 3. Develop 4. Meronts 2. Mature in diverse intestinal into 8 release extra- wall merozoites merozoites cytoplasmic vacuoles 5. Second round of infection: some cells will develop into gametocytes  Cryptosporidiosis – treatment / recovery Immunocompetent: Cryptosporidiosis and poverty Fluid and electrolyte replacement A major cause of childhood(