Eukaryotic Pathogens: Algae and Protozoans What types of eukaryotic organisms are pathogenic, and how do they differ from bacteria?Algae:”Plant-like Protists” Based on NutritionToxic Algae: Photosynthetic DinoflagellatesSlide 4The Protozoa: Kingdom ProtistaProtozoa: “Animal-like Protists” Based on Nutritional ModePathogenic ProtozoansSlide 8Important Pathogenic ProtozoansAmoebic dysentery (Entamoeba histolytica)Slide 11Severe colitis/dysentery( Balantidium coli) A CiliateSlide 13Archaezoa: Troublesome FlagellatesGiardiasis -Beaver fever (Giardia lamblia)Trichomoniasis (Trichomonas vaginalis)Trypanosomiasis/African Sleeping Sickness (Trypanosoma brucei)Slide 18Malaria (Plasmodium vivax) An ApicomplexanPlasmodium: An ApicomplexanToxoplasmosis (Toxoplasma gondii)Cryptosporidium (An Apicomplexan)Slide 23PowerPoint PresentationEukaryotic Pathogens: Algae and ProtozoansWhat types of eukaryotic organisms are pathogenic, and how do they differ from bacteria?•Algae: dinoflagellates and saxitoxin•Protozoans•Classification and special structures•Pseudopodia, flagella, cilia•Pellicles, cysts•Important protozoan pathogens•Amoebic dysentery •Balantidiasis (Balantidium dysentary)•Giardia, Trichomoniasis, Trypanosomiasis•Malaria, CryptosporidiumEukaryotic pathogens are mostly parasitic and are difficult to target selectively with drugs since their cells are so similar to human cells.Algae:”Plant-like Protists” Based on NutritionTable 12.1•Cellulose in plasma membrane•Unicellular•Algal “blooms” cause “red tides”•Shellfish ingest dinoflagellates; toxin concentrated through food chain•Neurotoxin (saxitoxin) causes paralytic shellfish poisoningToxic Algae: Photosynthetic DinoflagellatesEukaryotic Pathogens: Algae and ProtozoansWhat types of eukaryotic organisms are pathogenic, and how do they differ from bacteria?•Algae: dinoflagellates and saxitoxin•Protozoans•Classification and special structures•Pseudopodia, flagella, cilia•Pellicles, cysts•Important protozoan pathogens•Amoebic dysentery •Balantidiasis (Balantidium dysentary)•Giardia, Trichomoniasis, Trypanosomiasis•Malaria, CryptosporidiumEukaryotic pathogens are mostly parasitic and are difficult to target selectively with drugs since their cells are so similar to human cells.The Protozoa: Kingdom ProtistaTable 12.1•Eukaryotic•Unicellular•Chemoheterotrophs•Vegetative form is a trophozoite•Some produce cysts, or dormant forms (often the infective agent)•Some have an outer support layer: pellicle•Asexual reproduction by fission, budding, or schizogony; •Sexual reproduction by conjugationProtozoa: “Animal-like Protists” Based on Nutritional ModeFigure 12.16Pathogenic ProtozoansProtozoans can be studied according to their type of locomotion:• Amoebas (sarcodines) move using pseudopodia• Ciliates (ciliates) move using beds of cilia• Flagellates (mastigophorans) move using one or more flagella• Apicomplexans are non-motile, intracellular parasitesEukaryotic Pathogens: Algae and ProtozoansWhat types of eukaryotic organisms are pathogenic, and how do they differ from bacteria?•Algae: dinoflagellates and saxitoxin•Protozoans•Classification and special structures•Pseudopodia, flagella, cilia•Pellicles, cysts•Important protozoan pathogens•Amoebic dysentery •Balantidiasis (Balantidium dysentary)•Giardia, Trichomoniasis, Trypanosomiasis•Malaria, CryptosporidiumEukaryotic pathogens are mostly parasitic and are difficult to target selectively with drugs since their cells are so similar to human cells.Important Pathogenic Protozoans• Amoebas• Entamoeba histolytica - amoebic dysentery• Ciliates• Balantidium coli - Severe colitis/dysentery• Flagellates• Giardia lamblia - giardiasis/beaver fever• Trypanosoma brucei -trypanosomiasis/African sleeping sickness• Trichomonas vaginalis - trichomoniasis• Apicomplexans• Plasmodium vivax - malaria• Toxoplasma gondii - toxoplasmosisAmoebic dysentery(Entamoeba histolytica)Amoebic protozoanPathogenic Protozoans• Amoebas• Entamoeba histolytica - amoebic dysentery• Ciliates• Balantidium coli - Severe colitis/dysentery• Flagellates• Giardia lamblia - giardiasis/beaver fever• Trypanosoma brucei -trypanosomiasis/African sleeping sickness• Trichomonas vaginalis - trichomoniasis• Apicomplexans• Plasmodium vivax - malaria• Toxoplasma gondii - toxoplasmosisSevere colitis/dysentery( Balantidium coli)A CiliateParasite primarily of cows, pigs and horsesSeen mostly in farm workers and other rural dwellers by ingestion of cysts in fecal material of farm animalsSymptoms similar to amoebic dysentery but milder.Only known pathogenic ciliated protozoanPathogenic Protozoans• Amoebas• Entamoeba histolytica - amoebic dysentery• Ciliates• Balantidium coli - Severe colitis/dysentery• Flagellates• Giardia lamblia - giardiasis/beaver fever• Trypanosoma brucei -trypanosomiasis/African sleeping sickness• Trichomonas vaginalis - trichomoniasis• Apicomplexans• Plasmodium vivax - malaria• Toxoplasma gondii – toxoplasmosis•Cryptosporidium•No mitochondria•Multiple flagella•Giardia lamblia•Trichomonas vaginalis (no cyst stage)Archaezoa: Troublesome Flagellates Figure 12.17b-dGiardiasis -Beaver fever (Giardia lamblia)Trophozoite stageCysts shed in fecesFlagellated protozoanTrichomoniasis (Trichomonas vaginalis)Flagellated protozoanUnusual undulatingmembraneTrypanosomiasis/African Sleeping Sickness(Trypanosoma brucei)Tsetse fly (intermediate host)Flagellated protozoanPathogenic Protozoans• Amoebas• Entamoeba histolytica - amoebic dysentery• Ciliates• Balantidium coli - Severe colitis/dysentery• Flagellates• Giardia lamblia - giardiasis/beaver fever• Trypanosoma brucei -trypanosomiasis/African sleeping sickness• Trichomonas vaginalis - trichomoniasis• Apicomplexans• Plasmodium vivax - malaria• Toxoplasma gondii – toxoplasmosis•CryptosporidiumMalaria (Plasmodium vivax)An ApicomplexanAnopheles mosquitogametocytes in RBCApicomplexanprotozoanring stage in RBCsnonmotilePlasmodium: An ApicomplexanFigure 12.19Infected mosquito bites human; sporozoites migrate through bloodstream to liver of humanSporozoites undergo schizogony in liver cell; merozoites are producedMerozoites released into bloodsteam from liver may infect new red blood cellsMerozoites are released when red blood cell ruptures; some merozoites infect new red blood cells,