1. Introduction to Medical Mycology Ellabib MS Scribd.com
Lecture one
Introduction to Medical Mycology
Ellabib MS
Scribd.com
4/27/2017
Ellabib MS

2. What is Fungi? Mykes=Rays
Eukaryotic
Initiate disease in human and animals
Yeast or mold or both
fungi
mold
yeast
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3. Disadvantage and advantage
Over 400,000 species
150 species cause disease
Other non pathogenic species emerged
Food spoilage
Plant disease (70%), destroy timber, textile
Decay plant and animals in soil
Production of antibiotics such as
Organic acids, soya sauce such as
Genetic and biochemical scientific model
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4. Habitat free living (why) few are normal flora (candida, malazessezia)
infection originated from exogenous
traumatic or inhalation
don't contain chlorophyll
can’t synthesize macromolecules from CO2
lead a heterotrophic existing
saprobes, symbionts, commensal, parasites
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5. Pathogenicity of fungi
A bunch of fungi can cause disease due to
ability to adapt to host tissues
dermatophytes (metabolize keratin)
systemic fungi grow at 37Ć )systemic fungi)
and survive at low oxidation reduction state
some fungi have capsule
Melanin's confer resistance
to enzyme lysis
Cryptococcus neoformans
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6. Structure of fungi Cell wall chitin and glucan sporopollenin
Plasma membrane
ergosterol
Nucleus
Double membrane with pores
rich in RNA
Cytoplasm
mitochondria, vacuoles and so on
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7. Morphology of fungi non motile reproduce by spores which form
mold or yeast or both
depending on fungal species
growth condition (Temp, Nutrient)
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8. Mold form (filaments form)
spore germinate
Filament (hyphae)
Divide by septa
Uni or multinucleated
Some fungi have no septa (Coenocytic hyphae)
Zygomycota
Mycelium
A mass of hyphae
Aerial mycelium for?
Submerged mycelium for ?
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9. Types of septa (important for classification)
Simple solid plate with out pores
With single pores
With several pores (sieve-like appearance)
Ascomycota and Deuteromycota
Barrel shaped apparatus called dolipore
Hook-like bridge between cells (clamp-connection)
Basidiomycota
Mycelium arrangement
Simple
Form complex tissue
Hyphae loss its individuality
Take column, rope, ball and other forms
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10. Types of Septa
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11. Yeast form Spore germinate Oval, round, elongated single cell
Reproduce by budding
Some by fission
Moist or mucoid colonies
Pseudohyphae
True hyphae
Depend on growth condition and species
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12. candida
P. marneffeia
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13. Dimorphic fungi Important mycotic agents?
Yeast form in host tissue (37Ć) or in vivo parasite
Mold or mycelium in 25Ć or environment saprobe
Histoplasma capsulatum, Sporothrix schenckii
Some have spherules with endospores
Coccidiodes immitis
Some produce sclerotia bodies (chromo-)
Some produce tick conidia (adiaspore)
Never reproduce inside host
Emmonisa parva
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14. Morphology of Dimorphic fungi
Histoplasma
Paracoccidiodes
Coccidiodes
Chromoblastomycosis
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Blastomycosis

15. Growth Mycelium Grow equally in all direction
This wall is rigid
Only the tip wall is plastic and stretches
Mycelium
Grow equally in all direction
Circular colony in solid medium
Globose colony in liquid medium
Most fungi grow at 25Ć
Some are grow at 37-50Ć
Aspergillus fumigatus, Cladosporium trichoides PH
6.6 to 6.8
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16. Nutritional requirements (glycogen)
Absorb rather than digest (decomposer)?
Require organic compounds
Facultative parasites
Few are obligate parasites?
Rhinosporidium seeberi
Loboa loboi
Carbohydrates (glucose) best carbon source
Organic or inorganic nitrogen (ammonium compounds)
Some require vitamins (anthropophilic dermatophytes)
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17. Heterotrophic by Absorption
Fungi get carbon from organic sources
Hyphal tips release enzymes
Enzymatic breakdown of substrate
Products diffuse back into hyphae
Product diffuses back
into hypha and is used
Enzymatic breakdown
Products
Nucleus hangs back
and “directs”
Enzymes
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18. Reproduction why? important
Asexual (anamorphic state) clinically and for propgation
In filaments fungi
Free cell formation inside sporangium
Zygomycota
Zygospores or sporangiospore
Budding out as new structure
Fragmentation of the fertile hyphae
Conidia (Ascomycota and Basidiomycota, Deuteromycota
Pattern of conidia
Thallic conidia produce from entire parent cell
Blastic conidia from part of parent cell
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19. Asexual reproduction in mold form
Thallic conida
Blastic congia
sporangiospores
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20. Yeast Asexual reproduction Budding such as candida species
Fission such as Pencillium marneffei
AIDS Patients
Sexual reproduction (Teleomorph state)
Zygomycota, Ascomycota and Basidiomycota
Based on fruiting structure
Fungi lacking sexual stage
Deuteromycota (Fungi imperfectii)
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21. Types of sexual reproduction why
Homothallic
Thallus is self-fertile
Heterothallic
Thallus is self-sterile
Stages of sexual reproduction
Plasmokamy
Karyokamy
Meiosis (reduction division)
Formation of diploid nucleus
Mitosis to form haploid nucleus
Sexual spores
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23. Sexual reproduction in Zygomycota
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24. Sexual spores Remain attach to hyphae Zygospores (Zygomycota)
Rhizopus, Mucor and Absidia
Remain in side sac called ascospores (Ascomycota)
Histoplasma, Dermatophytes, Peidraia hortae
Spore reside on basidium called basidiospores
Basidiomycota
Cryptococcus neoformans
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25. Types of Sexual spores zygospore Basidiospores Ascospores 4/27/2017
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Ascospores

26. Phylum of Deuteromycota
Lacking sexual phase
Candida species, Malassezia furfue
Epidermophyton floccosum, American coccidiodes
Classification or taxonomy of fungi
Basic rank is species
Grouped in system of genera
Families, classes, phyla or division
Kingdom
Varieties
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27. Filobasidiella neoformans
Sexual stage of Cryptococcus neoformans
Kingdom Fungi
Phylum Basidiomycota
Class Heterobasidiomycetes
Order Filobasidiales
Genera
Species
Varieties
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