Introduction to Fungi (Mycology) Flashcards
(22 cards)
How many fungi are humans actually susceptible to?
200
What are conidia?
Conidia are asexual reproductive elements
What are spores?
Spores are sexual reproductive elements
What are the two ways that fungi differences are exploited for medical use?
Fungi have a rigid cell wall, containing chitin, that can be visualized after treatment with 10% KOH.
Instead of cholesterol, fungi have membranes with ergosterol which is a target for antifungal drugs
Are yeasts multicellular or single cells?
Yeasts are single cells
Are molds multicellular or single cells?
Molds are multicellular
What are hyphae?
Tube-like extensions developed by molds
What are the two structures of hyphae?
Septate and non-septate
What is an intertwined mass of hyphae?
Mycelium
What does the ability to grow dimorphically mean?
It means that in certain conditions, it can grow as either a yeast or mold. Yeasts are typically found in tissue and at 37C, while mold forms at room temp.
What 3 types of problems to fungi cause?
Allergies, mycotoxicoses (ie mushroom poisoning) and mycoses (true infections)
From least to most severe, what are the five classifications of bacteria?
Superficial mycoses, cutaneous mycoses, subcutaneous, systemic, opportunisitic
What is the most pathogenic category of fungal infections?
Systemic, while more deaths result from opportunistic because they are immunocompromised.
What is the main way of catching a systemic fungal infection?
Inhaling conidia or spores
Why has the incidence of mycotic patients increased within the last year?
We are keeping immunocompromised patients, like HIV patients, alive longer. Thus, they are exposed to more fungi.
What are three ways fungi can cross a barrier to cause infection?
Mechanical breaks, inhalation, invasive hyphae formation
Why do normal healthy individuals have good tolerance of fungal infections?
Opportunistic molds are sensitive to neutrophils
T-cell immunity is of primary importance
Antibodies can play a role in preventing infxn
Much of the damage is from the immune response
What is sabouraud’s medium?
A low pH, high glucose environment that promotes the growth of fungi while hampering growth of bacteria.
What are some problems with antifungal drugs?
They target eukaryotes, so they are toxic
Many treatments fail or relapse
What are common fungal targets of antifungal treatment?
Cell wall, ergosterol (fungal membrane), genome replication
How are localized or superficial infections treated?
Topical cream or observation
HOw are disseminated infxns treated?
Oral meds or IV
