Download presentation
Published byellabib@gmail.com Ellabib Modified over 9 years ago
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 4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
7
Morphology of fungi non motile reproduce by spores which form
mold or yeast or both depending on fungal species growth condition (Temp, Nutrient) 4/27/2017 Ellabib MS
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 ? 4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
10
Types of Septa 4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
12
candida P. marneffeia 4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
14
Morphology of Dimorphic fungi
Histoplasma Paracoccidiodes Coccidiodes Chromoblastomycosis 4/27/2017 Ellabib MS 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 4/27/2017 Ellabib MS
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) 4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
19
Asexual reproduction in mold form
Thallic conida Blastic congia sporangiospores 4/27/2017 Ellabib MS
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) 4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
22
4/27/2017 Ellabib MS
23
Sexual reproduction in Zygomycota
4/27/2017 Ellabib MS
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 4/27/2017 Ellabib MS
25
Types of Sexual spores zygospore Basidiospores Ascospores 4/27/2017
Ellabib MS 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 4/27/2017 Ellabib MS
27
Filobasidiella neoformans
Sexual stage of Cryptococcus neoformans Kingdom Fungi Phylum Basidiomycota Class Heterobasidiomycetes Order Filobasidiales Genera Species Varieties 4/27/2017 Ellabib MS
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.