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10-FUNGI.Pdf هذا العمل ﻻ يغني عن المرجع اﻷساسي للمذاكرة Lecture 10 Fungi Objectives: • To describe the general characteristics of fungi and recognize a fungus from all other living organisms. • To establish familiarity with the terminology needed by medical students. • To know certain fundamental facts about classification reproduction and identification of fungi. General Characteristics Of Fungi Myco Mycology: Study of fungi, (Kingdom Myceteae = kingdom Fungi) = Fungus in Greek in = Fungus Medical mycology: Study of medically important fungi and their diseases Mycoses: A disease caused by a fungus Saprobic: feed on dead All Eukaryotic tissues or organic waste (a true nucleus) (decomposers) Symbiotic: mutually beneficial Heterotrophic: relationship between a fungus and another organism Parasitic: feeding on living Do not have chlorophyll tissue of a host (Achlorophyllous) (disease) Extra: Cell membrane (Sterol, Ergosterol) Mannan and Glucan Chitin Characteristics of fungi:Characteristics are targets The cell is surrounded by a for the rigid cell wall made of: diagnosis of Complex carbohydrates fungal (Mannan, Glucan) infections. Morphology Types of morphology: Yeasts: Filamentous "Mold" fungi: unicellular (Hyphae, Dimorphic organisms mycelium) Hyphae are multicellular Yeast: filamentous Filamentous: Parasitic form, structures, Saprophytic form, Tissue form, constituted by Cultured at 25 C Cultured at 37° C tubular cells with cell walls. Dimorphic: Have two forms depending on change in the environmental factors (Ex: Temperature) Mold form Yeast form Yeasts Morphology: Reproduction: Examples: Clinical Examples: Candida Albicans (found as normal flora) Colony Budding Pseudohyphae Extra: Pseudo = not true hyphae (Asexually) Saccharomyces but it still a yeast cerevisiae (found in Baking Powder) Saccharomyces Candida Albicans Pseudohyphae Yeasts budding cerevisiae stained Filamentous (Mold) fungi A hypha: Mycelium: Conidia/Spore: Examples: (plural hyphae) (colony) Aspergillus (Extra: very common is a long, branching pathogenic filamentous fungi) filamentous cell. The intertwined mass asexual spores born hyphae are the main of hyphae that forms externally on hyphae Penicillium mode of vegetative the fungal colony. or on a conidiophore. (Extra: synthesize penicillin) growth. Rhizopus (Extra: causes Black bread mold) Aspergillus Penicillium Rhizopus species Selected Features of Fungi and bacteria compared Selected Features of Fungi and bacteria compared Fungi Bacteria Cell Type Eukaryotic Prokaryotic Sterols absent, except in Cell Membrane Sterols present Mycoplasma Glucans, mannans, chitin Cell Wall Peptidoglycan (no peptidoglycan) Sexual and asexual reproductive Endospores (not for reproduction), Spores spores some asexual reproductive spores Hetrotrophic, autotrophic, Limited to hetrotrophic, aerobic, Metabolism aerobic, facultatively anaerobic, facultatively anaerobic anaerobic Filamentous (mold) fungi The threads (hyphae) are actually tubular cells that, in some fungi, are partitioned into segments (septate); whereas, in other fungi, the hyphae are uninterrupted by cross walls (nonseptate). Mycelium is the intertwined mass of hyphae that forms the fungal colony , and conidia is spore produced asexually by various fungi at the tip of a specialized hypha. Examples: penicillium, aspergillus and rhizopus MORPHOLGY Moniliaceous Dematiaceous molds: Molds: Are pigmented. hyaline or lightly Because of the pigmented e.g. Aspergillus, pigment, the conidia or Penicillium colonies appear hyphae, colorless dark, brown, or black Reproduction in Fungi Reproduction in Fungi Asexual (Only undergo mitotic Sexual cell division) Meiosis of this Fusion of two transient diploid Spores compatible Mitosis to form a Somatic become sexual formation strains of the transient diploid (Asexual sporulation) spores same species (ascospores) Yeasts by Molds by hyphal budding fragmentation PATHOGENICITY OF FUNGI Spores: These are the small airborne particles by which fungi reproduce, they are produced and disseminate in the air. Fungi can cause diseases to humans Cause superficial infections some can cause allergic reactions Few cause invasive infections Not all fungi are pathogenic, to cause the disease: Thermotolerance Ability to survive in tissue environment Ability to withstand host defenses Online Quiz Fine! Just click HERE Videos -What is a fungus? - Overview of the Fungal Cell Structure. - Crash Course Biology. Books that could help you Lippincott’s Illustrated Reviews : Microbiology Second Edition. Lippincott’s Microcards Microbiology Flash Cards Third Edition. Girls Team Boys Team • Lamya Alsaghan • Nojood Alhaidri • Ali Alzahrani • Monera Alayuni • Khalid Sharahily • Alanoud AlOmair • Ahmad Alzahrani • Shahad Alenezi • Zeyad Alsalem • Aisha Al-Sabbagh • Muhammad Dossary • Bodour Julaidan • Meshal Alhazmy • Noura AlTawil • Hamzah Alfiar • Deema AlFaris • Sara Al-Hussein • Suha Alenezy • Latifah Alsukait [email protected] • Dalal Alhuzaimi • Reema Allhaidan @microbiology435 Contact us! http://ask.fm/microbiology435 إن أصبنا فمن هللا عز وجل، وإن أخطأنا فمن أنفسنا والشيطان .
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