Fungi 1 Lecture 23 Summer, 2004 Demosthenes Pappagianis, M.D., Ph.D.
MMI 480B The scope of medically important fungi Possible outcomes in interaction between infectious agent and the host
Infection subclinical (inapparent) healed latent reactivation healed illness healed death clincally apparent acute recovery healed relapse fulminating death recovery chronic death persistent recovery healed relapse healed death Mold colony Microsporum canis Mold hyphae and conidia Yeast colony- Candida albicans Budding yeast Cryptococcus neoformans Dimorphism in Mucor species Fungal Cell (Eukaryotic)
Capsul (CHO) Mitochondrion Wall , glucan mannan chitin protein Golgi-like ductyosome Glycogen Microbody catalase Vacuole Lomasome Microtubules Nucleus pore nucleolus envelope Cytoplasmic membrane eroosterol Ribosomes (80S) Endoplasmic reticulum Properties of Infectious Agents
(From Dr. Beamans Lecture 1) Virus Prokaryotic cell Eukaryotic cell 1.Relative size (diameter) 2.Nucleic acid 3.Nuclear membrane 4.Chromosomes/cell 5.Histone bound DNA 6.Mitotic division 7.Protein 8.Enzymes 9.Ability to produce energy 10.Cytoplasmic ribosomes 2.0 m more than one (80S) 11.Organellar ribosomes 12.Mitochondria 13.Chloroplasts 14.Structured outer coat(notmembrane) 15.Cytoplasmic membrane 16.Free living 17.Endoplasmic reticulum 18.Golgi apparatus 19.Membrane bound structured cilia or flagella 20.Simple flagella (not membrane bound) - -/+ (cell wall) +/- + (most) Plants (cell wall) fungi & plants + (if present) 21.Cytoplasmic streaming 22.Ameboid movement 23.Phagocytosis & pinocytosis 24.Storage inclusion bodies 25.Microtubules 26.Mesosomes (intracytoplasmicmembranes) 27.Lipids 28.Polysaccharides 29.Non-unit membrane gas vacuoles 30.Unit membrane-boundvacuole 31.Centriole -(some exceptions) +/- KOH mount of skin with hyphae Calcofluor stain - P. brasiliensis Adrenal Gland - Histoplasmosis
H & E stain Methenamine silver Fungi - vegetative growth
Yeast Mold Asexual Spores Anti-fungal Agents Life Cycle of Rhizopus stolonifer - zygomycete Basidiomycete Ascomycete The scope of medically important fungi Various Exposures and Influences of Mycotoxins
Anaissie, et al Aspergilllus flavus Colony Aflatoxins Edible mushrooms Toxic mushrooms a-amanitin Ergot fungus Claviceps purpurea
Rye Wheat Ergot Alkaloids Amine Alkaloids Peptide Alkaloids Mycotoxins and Their Biological Effects
Organism Aflatoxins Hepatocarcinogen A. parasiticus, A. flavus Trichothecenes (T-2, nivalenol, deoxynivalenol, satratoxins, DAS*) Dermal toxicity; impairment of immune system; inhibit protein synthesis, teratogen* Fusarium, Acremonium, Stachyobotris, Trichoderma, Trichothecium, Verticimonosporium Anthraquinones (luteoskyrin, rugulosin, iridoskyrin, emodin) Hepatotoxic, hepatocarcinogen or mutagen Penicillium, Aspergillus Citreoviridin Neurotoxin; inhibits mitochondrial ATPase activity, reduces glycogen synthetase activity Penicillium Naphtoquinones (xanthomeganin, viomellein) Hepatotoxic Trychophyton, Penicillium viridicatum Ochratoxins Inhibit phe-tRNA synthase Aspergillus, Penicillium Zearalenone (F-2) Estrogenic, teratogenic Fusarium graminearum Chloropeptide (islandi-toxin) Hepatotoxin, decreases hepatic glycogen synthase activity Penicillium islandicum *DAS = diacetoxy-12, 13-epoxytrichotece-9-ene