MYCV311 Preliminary Lecture PDF

MYCV311 PRELIM LECTURE TOPIC #1 ✓ Grow at high temperature (37 C) MS. HAULA GUIAMALODDIN ✓ Subject to incubation to grow INTRODUCTION TO MYCOLOGY...

MYCV311 PRELIM LECTURE TOPIC #1 ✓ Grow at high temperature (37 C) MS. HAULA GUIAMALODDIN ✓ Subject to incubation to grow INTRODUCTION TO MYCOLOGY STRUCTURE − HYPHA/HYPHAE: BENEFICIAL ACTIVITIES OF FUNGI ✓ Shape − Nutritional fungi such as mushroom ✓ Pigmentation ✓ Functions Food Mushroom ✓ Cross walls Food production Yeast for baking to expand the size of the bread − HYPHAE – long slender, branching tubes (basic structural form of or soften the bread. fungi) Fermentation of Yeast: to differentiate grape juice to wine/ beer- alcoholic drinks absorbing the CHO to convert in alcohol and − MYCELIUM – filamentous mass of hyphae carbon dioxide SHAPE Industrial production Yeast: for baking Shapes of Hyphae: Decomposition Decomposers/Commensal maintain ecosystem 1. Antler Hyphae – swollen equilibrium in the environment 2. Racquet Hyphae – club-like HARMFUL ACTIVITIES OF FUNGI 3. Spiral Hyphae – coiled − Destruction of materials – causes spoilage of the left-over food 4. Rhizoid Hyphae – branching − Spoilage of stores foods PIGMENTATION − Destruction of crops – storage of rice − Melanin – responsible for the color/pigmentation of the hyphae − Fungal infection (buni. hadhad, and alipunga) a. HYALINE HYPHAE / MONOLIACEOUS – clear, colorless or blue ✓ Psoriasis – not a fungal infection but rather an b. DEMATIACEOUS HYPHAE / PHAEOIDS – dark or brown autoimmune disorder. − Masson-Fontana stainZ − Allergies − Mycotoxicosis – toxin content which produced by a fungus that was intake by a human. ✓ Aflatoxin (produced by Aspergillus spp.) − Toxin content found in Nagaraya − Improper storage can affect on the production of toxins in foods ADDITIONAL NOTES: − Fungi likes in moist/ acidic/ humid areas or environment − Can grow at room temperature FUNCTIONS GENERAL PROPERTIES − Achlorophyllous/Heterotrophic ✓ Absence of chlorophyl ✓ Lack photosynthesis ✓ Nutrients are obtained or absorbed through the environment − Neutral or Acidic Environment ✓ Acidic environment – one of the requirements to grow − Nucleated organisms ✓ Single-cell fungus Mycelia – filamentous mass of hyphae ✓ Multi-nucleated fungus 2 TYPES: − Obligate aerobes: fungi require oxygen to grow A. Aerial Mycelia – found in the surface/top of the agar that is − Facultative anaerobes: fungi can grow with or without oxygen responsible for the reproduction/replication B. Vegetative Mycelia – found below the agar that is responsible for PROPERTIES FUNGI BACTERIA the absorption or obtaining the nutrients Kingdom Eumycota Procaryote Nucleus Eukaryotic: nuclear Prokaryotic: no membrane: CROSSWALLS membrane: nucleoid: only one more than one chromosome: “chromosome” mitosis Cytoplasm Mitochondria: No mitochondria: Endoplasmic reticulum: 80S no endoplasmic reticulum: ribosomes 70S Ribosomes Cytoplasmic Sterols (Ergosterol) No sterols membrane Bacteria that have Ergosterol: Ureaplasma and Mycoplasma Cell wall Glucans, mannans, chitin, Peptidoglycan: Murein, Cross walls – pertaining to the cellular separation chitosan teichoic acids (gram-positive), 2 TYPES: Major composition: proteins polysaccharides or a. Septated Hyphae - presence of septa/septum that separates the carbohydrates nucleus (also presence of line) Metabolism Heterotrophic: Heterotrophic: b. Coenocytic Hyphae (non-septated/sparsely septated) – absence/ mostly aerobes: no Obligate aerobes and not visible of septum or septa that separates the nucleus photosynthesis Absorbed anaerobes, facultative nutrients from environment anaerobes NOTES: Size, mean Yeast cells: 3-5-10 um 1-5 um diameter Molds: indefinable − Sparsely septated mostly seen in Zygomycetes species: Dimorphism In some species None Rhizopus Absidia FUNGI Mucor racemosus − Single cell fungus- Yeast Cunninghamella − Multinucleated fungus: Molds/Moulds Lichtheimia − Uni or Multinucleated SPORES − Possesses: a. ASEXUAL SPORES – usually mitotic nuclear division happens ✓ Monomorphic – either Yeast or Molds b. SEXUAL SPORES – presence of nuclear fusion and undergo meiosis ✓ Dimorphic – Yeast/Molds − Molds ASEXUAL SPORES ✓ filamentous type Blatospores Chlamydospores ✓ Jawetz or Mahon’s: (Room temperature: 22- 25 C) Sporangiospore Conidiospores ✓ Henry’s: (Room temperature: 25-30 C) Arthrospores − Yeasts – pasty/mucoid form Blastospores – budding MEDICALLY IMPORTANT PHYLA OF KINGDOM FUNGI Phylum Zygomycota Phylum Ascomycota Phylum Basidiomycota Phylum Deuteromycota Phylum Zygomycota (aka Conjugation fungi) − About 600 species Chlamydospores − Terrestrial saprophytes − rounding form/ enlargement − Multinucleated mycelium lacking cross walls − intercally - within the hyphal segment − Coenocytic hyphae / sparsely septated − sessile- side − Asexual spore: sporangiospore − terminal - end − Sexual spore: zygospore − Candida albicans: corn meal agar with tween 80 Phylum Ascomycota (aka Sac fungi) Sporangiospore − Largest group of fungi − Enclosed in a sac − Terrestrial, marine, and freshwater spp. − aka Sporangia − Hyphae or mycelium with perforated cross walls with one or more nuclei (septated hyphae) − Sporangiophore - connected to hyphae that supports sporangia (special structure) − Sexual: Ascospores − Asexual: Conidiospore Conidiospores − Fungi: Blastomyces, Histoplasma capsulatum, Trichophyton − not enclosed in a sac − aka Conidia Phylum Basidiomycota (aka Club fungi) − Conidiophore – supports the conidia − Mycelium with cross walls − Conidiogenous cell (Phialides) – vase shape − Sexual: Basidiospore – fusion with conidia that connects to hyphae then supports the − Asexual: Conidiospore conidiophore and then will support to conidia − Fungi: Malassezia, Trichospora, Cryptococcus neoformans Arthrospores Phylum Deuteromycota (aka Fungi imperfecti) − barrel shaped − Imperfect fungi − fragmentation of septated hyphae − Most of the pathogenic fungi − Disjunctor cell – spaces between the arthrospores − Septated hyphae − Asexual: Conidia − No mode of sexual reproduction − Causative agent of mycoses (fungi-causing disease) SEXUAL SPORES Zygospore Ascospore Basidiospore Oospore Zygospore – within a thick-walled hypha, fusion of 2 identical cell Ascospore – septated within the segment Basidiospore – aka basidia; basidium (mushroom); where replication occurs Oospore – fusion of 2 unidentical cell NOTE: − Basidium – a unique feature of basidiospore that supports basidia. SPECIMENS FUNGI MORPHOLOGY STAINS USED IN MYCOLOGY YEAST − Mucoid form of the fungi − Non-filamentous, unicellular fungi − Spherical or oval Produced asexually − Col. Morph: moist, cream, opaque or pasty on media − Grows at high temp. and subjected to incubation: 37 C MOLDS − Filamentous type of fungi − Long filaments of cells joined together, end to end − Can grow as: Hyphae and Mycelium − Col. Morph: fluffy, cotton, wooly or powdery colonies − Grows at RT: 22-25 C / 25-30 C NUTRITIONAL GROWTH CHARACTERISTICS − Acidic environment − Obligate aerobic − Some are facultative anaerobe − Resistant to osmotic pressure − High CHO content ✓ Culture media that has a high content of CHO (that is − absorbed by the fungi for them to reproduce or grow) − High salt concentration − Less nitrogen − Metabolize complex CHO  MEDIUM USED FOR ISOLATION Sabouraud Dextrose Agar (SDA) ; (high content of CHO) − General medium, pH: 5.6 inhibits bacteria, grows molds and yeast Sabouraud Dextrose Agar w/ antibiotics − Antibiotics inhibit fungal contaminants and bacteria. − Dermatophytes and most fungal pathogens now. Brain-heart Infusion Agar (BHIA) − For isolation and conversion of dimorphic fungi from mold to yeast phase. − Used for normally sterile specimens (CSF, pleural fluids) Brain-heart Infusion Agar w/ antibiotics − Selective medium used for isolation of pathogenic fungi from specimens contaminated with bacteria. Inhibitory Mold Agar − For recovery of fungi from specimens contaminated with bacteria. − Contains chloramphenicol and gentamicin to inhibit bacteria. Dermatophyte Test Medium − For recovery of dermatophytes from skin, hair and nails. − Turn agar from yellow to red. Antibiotics inhibit bacteria. FOR IDENTIFICATION Potato Dextrose Agar − Stimulates sporulation of molds. Good for slide cultures. − Alternative agar for SDA. Cornmeal Agar w/ Tween 80 − Preferred media to differentiate Candida species. C. albicans (causes vaginitis) produces chlamydospores Urea Agar − Detection of urease production by C. neoformans Birdseed Agar (niger seed or caffeic agar) − Isolation of C. neoformans. Black-brown colonies in 4-7 days ANTIFUNGAL AGENTS Polyene antibiotics − they combine with the sterol causing the destruction of cell − membrane/ cytoplasmic membrane − Targets sterol Imidazole Compounds − targets the P450 enzymes system (attached to mitochondria) Polyoxin Compounds − inhibits the chitin synthesis in the cell wall − inhibits the replication of the fungi − Systemic fungal disease – First to prescribed by the physician is the Amphotericin B (depends on the dosage) with polyoxin compound.