Mycology Flashcards
What is mycology?
The study of fungi
Where are fungi found in the environment?
EVERYWHERE
Are fungi Eukaryotes or Prokaryotes?
Eukaryotes
T/F: Fungi are free living organisms
TRUE
The majority of fungi are _______
non-pathogens
T/F: Fungi that are saprophytes are pathogenic
FALSE
Heterotrophs are pathogenic
How do fungi reproduce?
Asexually - fragmentation and budding through spores
Sexually reproduction is seen in some fungi
What are two important components of fungi cell membranes?
sterols and ergosterol
**these can be targeted for treatment
T/F: Fungi cell walls include cellulose
FALSE
glucan, mannan, and chitin
NO cellulose
Are yeast unicellular or multicellular?
UNICELLULAR
Is mold unicellular or multicellular?
MULTICELLULAR
Mold has hyphae and fruiting bodies which contain ______
SPORES
A group of tangled hyphae is called a ________
Mycelium
What is special about dimorphic fungi?
They can grow as yeast or mold depending on the temperature
At what temperatures does dimorphic fungi grow as yeast?
Temperature it will grow as mold?
HIGH temp (body temp) = Yeast
Lower temp (room temp) = mold
**these are HIGHLY PATHOGENIC fungi
What divides hyphae making them segmented?
septa
Can have Septate vs non-septate hyphae
If hyphae is pigmented dark, it is _________ fungus.
If hyphae is non-pigmented it is ________ fungus
Dark - dematiaceaous fungus
No pigment - hyaline fungus
When fungus invades the tissue and induces its pathogenic effect, that is a _________ _____
Fungal infection
What is mycotoxicosis?
Fungal contamination or growth on food that leads to accumulation of toxins. When consumed, the toxins will induce severe dz
NOT A FUNGAL INFECTION
T/F: Fungi can induce allergic reactions or hypersensitivities
TRUE
Who are the typical host of environmental fungal infections?
Immunocompromised
Fungi are opportunistic
Characteristically, fungi will induce chronic, ______ infections
granulomatous
T/F: there are many different antimicrobial treatment options for fungal infections
FALSE
Limited
Is under diagnosis a problem causing the rate of fungal infections to rise?
YES
What are the different variations of fungal infections? (where they infect)
Superficial - limited to outer most layers of skin and hair
Cutaneous - extend deeper
SQ - infections involving the dermis, subQ tissue, muscle and fascia
SYSTEMIC - primarily in the lung but can spread to other organs
T/F: using immune response is one way to dx fungal infections
TRUE - Agar gel immunodiffusion and ELISA
What is an easy test that can be performed in your clinic to test for superficial fungal infections?
Use tape to make an impression smear and use India Ink - to make wet mount
T/F: Histopathology is not a helpful test when looking to dx a fungal infection
FALSE
fungus can be seen in histo
What special stains might you use to dx a fungal infection via cytology?
India ink (impression smear) KOH (hair or fresh tissue) Calcofluor stain (fresh tissue) ** requires UV microscope
What special media is used to grow fungus and why?
Special media needed for growth - but also use it to inhibit bacterial growth (low pH)
Sabouraud Dextrose Agar
What media can you use in house to use for fungal culture?
Dermatophyte test media
Scotch tape prep and LPCB stain
What diagnostics are used to get a definitive identification of fungus?
DNA probes and sequencing
Exoantigen and serotyping
Mating studies
virulence testing
T/F: Majority of antifungal drugs inhibit sterol/
FALSE
Majority inhibit ERGOSTEROL (component of the cell wall)
What antimicrobial inhibits DNA synthesis?
Flucytosine
What is the MOA of Griseofulvin and what type of fungus is it used for?
Inhibits Mitosis - it accumulates in keratin
Used for dermatophytes only
T/F: Fungal susceptibility is often done in conjunction with a fungal culture
FALSE
these are rarely done, not easy to do
Is the cell mediated immunity or humoral immunity more active when there is a fungal infection?
cellular*** dominates
antibodies can be made but are not effective for protection
What fungus is responsible for a phaeohyphomycosis?
Dematiaceous (brown pigmented) fungus
T/F: Zygomycetes are fast growing, terrestrial, largely saprophytic fungi
TRUE
Mycetoma is a mycotic infection caused by a number of different fungi and what bacteria?
Actinomycetes
*characterized by draining sinuses, granules, and tumefaction
Rounded sclerotic bodies are characteristic of what kind of fungal infection?
Chromoblastomycosis
