CSF-6250 Integrative Pathophysiology & Biomechanics in Health Care 2 PDF

CSF-6250 Integrative Pathophysiology & Biomechanics in Health Care 2 Module: Microbes in Human Health and Disease Unit 04 – Fungi, Parasites, and Vectors Verena Van Fleet, PhD, MS, MEd P...

CSF-6250 Integrative Pathophysiology & Biomechanics in Health Care 2 Module: Microbes in Human Health and Disease Unit 04 – Fungi, Parasites, and Vectors Verena Van Fleet, PhD, MS, MEd Professor, Department of Basic Sciences Unit 4 Objectives – List the three groups of eukaryotic agents of infectious diseases and recognize features typical for each group – Differentiate vectors from etiologic agents of infectious diseases – Recognize forms of asexual reproduction in microorganisms NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 2 Lesson 1: Introduction NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 3  The Scope of Medical Microbiology Increasing Complexity Etiologic Agents of Infectious Diseases Cellular A-cellular Eukaryotes Prokaryotes Viruses (Viroids, Prions only in plants) Helminths Fungi Protozoa Bacteria Arthropod Vectors 4 Reproduction in Eukaryotes – More complex and variable than in prokaryotes – Many fungi and some protozoa reproduce sexually and asexually – Asexual reproduction in eukaryotes through mitosis: – Binary fission (similar to bacteria): – Budding: ↳ I cells ar sin are , Not the same size NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 5 Reproduction in Eukaryotes – Asexual reproduction in eukaryotes through mitosis (continued): – Schizogony: Schizont Merozoites Nucleus Multiple mitoses Cytokinesis cytoplandNORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu Malaria 6 Sexual Reproduction Requires the formation of gametes through the process of meiosis: Meiosis One diploid nucleus Four haploid nuclei (two sets of chromosomes) (one set of chromosomes each) For genetic variability, during meiosis – the ‘maternal’ and ‘paternal’ chromosomes get randomly reassorted into new sets – Recombination of genes through ‘cross-over’ process NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 7 Lesson 2: Fungi NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 8 The Significance of Fungi – Decompose dead organisms and recycle their nutrients – Help plants absorb water and minerals – 30% cause diseases of plants, animals, and humans – Can spoil fruit, pickles, jams, and jellies – Used for food and in manufacture of foods and beverages (Beer , bread ,Cheese) – Produce antibiotics (Drugs) – Serve as important research tools NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 9 Morphology of Fungi – Filamentous growth (hypha = fungal filament; plural is hyphae); many hyphae create a mycelium (typical for molds) ↳ Growth of mold A fungal mycelium – Yeast cells are single cells, which may form chains called ‘pseudo- hyphae’ – Dimorphic species of fungi can grow as hyphae or yeast cells (depends on growth conditions) NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 10 Nutrition/Growth of Fungi – Cell wall made of chitin (polysaccharide) – Acquire nutrients by absorption, after releasing lytic enzymes – Most are saprobes feeding on dead organisms – Some can derive nutrients from living plants and animals – Some trap and kill microscopic soil-dwelling nematodes ↳ Littleworms – Most fungi are aerobic – Many yeasts are facultative anaerobes (→ fermentation) – May use ionizing radiation as energy source NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 11 Reproduction in Fungi Asexual spores of molds – All use forms of asexual reproduction – Budding A budding yeast – Asexual spore formation (typical mold spores) NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 12 Reproduction in Fungi Most fungi also reproduce sexually – Fungal mating types are designated as + and – (morphologically indistinguishable) – In essence also go through meiosis and formation of ‘zyogote’ through fusion of haploid cells – Not relevant in pathogenic fungi NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 13 Lesson 3: Parasites and Vectors NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 14  Parasites I worms NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 15 Protozoa – Diverse group defined by three characteristics – Eukaryotic (animal-like ‘-zoa’) – Unicellular – Lack a cell wall – Motile by means – Cilia – Flagella – Pseudopodia (e.g., Entamoeba histolytica) – Except subgroup, apicomplexans (e.g., Plasmodium → Malaria) ↳ Non motile NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 16 Diverse Morphology of Protozoa Giardia Entamoeba Balantidium Trypanosoma Toxoplasma - > in Cats can causedefritiia NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu em 17 Typical Life Cycle of Many Protozoa Trophozoite stage is fragile In trophozoite stage: Obtain nutrients by phagocytizing bacteria, decaying organic matter, other protozoa, or the tissues of host Intestinal protozoa: Cysts can survive stomach acid 18 Parasitic Helminths – Why are these covered under ‘Microbiology? Parasitic worms have microscopic infective and diagnostic stages – Each species has a unique life cycle – Some require an intermediate host – Grouping: – Platyhelminths (flatworms) > recognize terms – Nematodes (roundworms) NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 19 Examples of Platyhelminths Microscopic, Example Worm diagnostic stage Beef Tapeworm Liver Flukes NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 20 Examples of Nematodes Microscopic, Example Worm diagnostic stage Hookworm Pinworm NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 21 Disease Vectors From two groups of arthropods: – Arachnida – Insecta NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 22 Arachnid Vectors – Ticks – Mites (chiggers) NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 23 Insect Vectors – Lice (1-2mm) Increasing in size – Fleas – Flies – Mosquitoes – Bugs (up to 1 inch long) NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 24 Summary – Reproduction in eukaryotes – Fungi – Protozoa – Helminths – Arthropod vectors NORTHWESTERN HEALTH SCIENCES UNIVERSITY | nwhealth.edu 25