L85-L88 Flashcards
Fungi are ___ cells; bacteria are ___ cells.
Eukaryotic; prokaryotic
What are two unique features of fungi that distinguish them from human eukaryotic cells?
- Chitin (rigid cell wall)
2. Ergosterol (predominant sterol)
What is budding?
Asexual fungal reproduction of single-celled yeasts
How do fungi with hyphae reproduce?
Asexually - bits of the hyphae break off and continue to grow as separate entities, or form stalks containing spores
How do fungi produce spores?
Sexually - two mating cells from hyphae of different strains fungi can mate by fusing together and forming a spore stalk
A solitary yeast cell can morph into either a ___ or ___.
Germ tube; blastoconidia
What do germ tubes become?
True hyphae with septa
What do blastoconidia become?
Pseudohyphae
What is the collective term for a mass of hyphae?
Mycelium = mold
What is the difference between sporangium and conidiophore?
Sporangium: enclosed sac containing spores
Condidiophore: specialized hyphal structure that bear conidia (spores)
What are arthroconidia?
Small barrel shaped structures that become spores by breaking off from hypha at septation points
What are chlamydoconidia?
Spores at the end of hyphae; contains stored food
What are macro and microconidia?
Small and large types of conidia in a fungus
What are dimorphic fungi?
Fungi that are yeast-like at 35 C and mold-like at 25 C
What are 4 important examples of dimorphic fungi?
- Histoplasma capsulatum
- Blastomyces dermatitidis
- Coccidioides immitis
- Sporothrix schenckii
How are fungi transmitted?
- Person-to-person (Athletes’ s foot)
- Contact with environment (inhalation of spores, traumatic inoculation)
- Contact with animals (poop, skin/hair)
Fungal ___ mediate colonization of epithelial surfaces.
Adhesins
What are some examples of fungi invading natural barriers?
- Trauma (rose thorns)
- Inhalation of spores (Coccioides in dust)
- Breakdown of mucosal barriers (catheters)
What are some examples of fungi avoiding phagocytosis?
- Histoplasma multiply in macrophages
2. Cryptococcus has a capsule
What type of host immunity is required to eradicate infection with fungi?
Cellular immunity (humoral is not protective)
What is the most common opportunistic fungal pathogen?
Candida
Where is Candida normal flora?
GI and GU tracts
How does Candida appear in body fluids?
Oval budding yeasts
How does Candida appear in tissues?
Yeasts with pseudohyphae