Intro to Mycology Flashcards
What is mycology?
Study of fungi: Yeast and mold
General structure of fungi
eukaryotic organism: nucleus, nuclear membrane, mitochondria, endoplasmic reticulum: cell wall made up of chitin and cell membrane: ergosterol
Mycology of Fungi
many are saprophytes few are parasities
aerobes: need oxygen
facultative aerobes: don’t require oxygen
Human fungal infections
nosocomial: originating in hospital
opportunistic infections: immunocompromised individuals
Classification of Medically Important Fungi
- yeast
- Yeast like Fungi
- Mold Filamentous Fungi
- Dimorphic Fungi.
Features of yeast
Example
unicellular
non-filamentous
reproduce via budding
round/spherical
e.g creptococcus neoformaus; india ink staining
culture on sabouraud’s dextrose agar- creamy white colony
gram stain positive- purple
Features of Yeast like Fungi
Example
part as yeast other as pseudohypha
reproduce by budding
e.g candida albicans: pseudomycelium
Culture on SDA creamy white colony
Gram stain is positive
Features of Mold/ Filamentous Fungi
Two examples
multicellular
filamentous
reproduce via spores
- Penicillium spp. : Lactophenol Cotton Blue Stain: stains chitin
SDA- powdery and blue green
conidia: brush or broom like arrangement - Aspergillus spp
SDA/PFA (potato flake agar) - green
Structure of Mold/Filamentous Fungi
Thallus- body: many hyphae
Hyphae- long filaments of cells
Septate hyphae: divided by cross walls (septa)
Aseptate hyphae- not divided by cross walls
Mycelium- many hyphae, filamentous, large
Features of Dimorphic Fungi
Can exists as both yeasts or molds depending on condition of growth (temperature)
mold form: aerial and vegetative hyphae
yeast form: reproduce budding
pathogenic fungi depends on temperature
yeast: 37 deg celc mold: 25 deg celc
What are the four systematic Classifications
- Deuteromycota
- Zygomycota
- Ascomycota
- Basidomycota
Deuteromycota? Examples
Reproduce asexually
e.g candida albicans- yeast infections & opportunistic infections in mucous membrane of AIDS patients
malassezia furfur (tinea versicular)- skin discoloration
Sporothrix schenckii- rose gardeners
Zygomycota? Examples?
aseptate hyphae
asexual via sporangia
sexual via zygospore
eg rhizopus- oppurtunistic infection diabetes patients
mucor
Ascomycota? Examples?
septate hyphae
asexual via conidia
sexual ascospore in ascus
e.g penicillium notatum- produce penicillium
aspergillus - carcinogenic aflatoxin in peanuts
blastomyces- respiratory infections
histoplasma capsulatum- resp & systemic infections
Basidiomycota? Examples?
septate hyphae
asexual rep. via budding e.g creptococcus neoformaus- causes oppurtunistic repiratory and CNS infections in AIDS ptients
amanita spp: mushrooms produce lethal toxins to humans
sexual rep. produce basdiospores
