Test 3-7 Clinical Mycology Flashcards
1. Appreciate the importance of fungi in human disease. 2. Describe the key characteristics of fungal cells and structures. 3. Categorize fungal infections based on tissue colonization. 4. Know the risk factors for acquiring fungal infections. 5. Know common antifungal agents and their targets (mechanism of action). 6. Become familiar with the techniques used to diagnose fungal infections and identify fungal pathogens.
fungus affects health in three ways:
1) allergens
2) toxin producers
3) infectious agents
fungi are what kind of organsim?
- eukaryotic! –> QUite similar to humans
- HAVE CELL WALL (NOT LIKE BACTERIAL NO PEPTIDOGLYCAN)
- MEMBRANE STEROL COMPOSITION (ergosterol instead of cholesterol - target for antivirals)
fungal cell wall made up of which polysaccharides and function?
- mannan (mannose), glucan(glucose), chitin (n-acetylglucosamine)
- shape, rigidity, str and protection
fungi memrane sterol component??
ergosterol
dimorphic
fungi that can grow as both yeast and molds
yeast details
- uniceulluar (spherical or ellipsoid
- reproduce via budding
bastocondia
buds are called this from budding - SURPRISE
molds
- have hyphae (mycelium) - fuzzy hair looking things, can be long and have cross walls = septa
- septa vs aseptate- has cross walls vs none (coenocytic)
vegitative mold
molds growing into a subrate
aerial mold
mold grows on top of a substrate
molds reproduction
-Asexual= produce conidia (reproductive unit
Micro-small ones
Macro-big ones
Chlamydo- (Arthro-) -Conidia which form within a hyphal element
-Sexual = produce spores (product of sexual union) look like conidia but got there sexually
mycelium
basically fancy term for hyphae – each little fuzzy strand of mold growing on something
pseudohyphae
basically hyphae that are connected to each other - branched like
fungal infection types
- SUPERFICIAL MYCOSES – infection of the outermost layers of skin and hair; Examples: Pityriasis versicolor, Tinea nigra, Black and White piedra
- CUTANEOUS MYCOSES – infection which extends deep into the epidermis as well as invasive hair and nail infections.; Examples: Dermatophyte infections; “ringworm”, “athlete’s foot”, “jock itch”
- SUBCUTANEOUS MYCOSES – infections involving the dermis, subcutaneous tissues, muscle, and fascia.; Examples: Sporotrichosis, Chromoblastomycosis
- SYSTEMIC MYCOSES – infections that originate primarily in the lung but may spread to any organ in the body.; Examples: Dimorphic fungi; Histoplasmosis, Blastomycosis, Paracoccidioidomycosis, Coccidioidomycosis. Cryptococcosis.
- OPPORTUNISTIC MYCOSES – infection associated primarily with immunosuppressed individuals.; Examples: Candidiasis, Aspergillosis, Zygomycosis, Pneumocystis jiroveci pneumonia.
host response/Immunity to fungal
- Innate immune system of a healthy individual is generally sufficient to prevent fungal infection: intact skin; pH; competition with the normal bacterial flora; epithelial turnover rate; desiccated nature of the stratum corneum; mucous membranes - antimicrobial peptides, ciliated cells
- When these protective barriers are breached fungi gain access to, colonize, and multiply in host tissues.
- Fungi can gain access to host tissues by traumatic implantation or inhalation.
The severity of disease caused by fungi depends upon
the size of the inoculum, magnitude of tissue destruction, the ability of the fungi to multiply in tissues, and the immunologic status of the host.
humoral role against fungi
small role