Mycology Flashcards
What are the general characteristics of Fungi?
- Chitin in cell walls
- Ergosterol in membranes
- Dimorphism (different structures at different temperatures)
- Form spores
- Natures decomposer
How do fungi exhibit dimophism? Which form when?
Two different forms dependent on temperature. Usually room temp is Mycelia, body temp yeast.
How are Fungi classified?
Based on their sexual spore type.
What are the common characteristics of pathogenic fungal agents?
- Can actively attack and invade tissue
- Exhibit dimorphism
- Endemic to certain regions, primarily in Americas
Describe each of the three clinical mechanisms of fungal disease.
- Infection: Most common, caused by presence in body
- Toxicoses: ingestion of poisonous mushrooms
- Allergies: inhalation of spores.
What are the 4 pathogenic fungi?
Blastomyces, Coccidoidoides, Histoplamsa, Paracoccidioides.
What does coccidoides form that is different inside the body?
Spherules, which are packets of yeast.
What are some characteristics of Blastomyces dermatitidis? Causes?
- Endemic to southeaster USA to canada
- Found in rich soils
- Inhalation of dust can carry spores of hyphal pieces
- Causes Blastomycosis (cutaneous or Pulmonary).
What are some characteristics of Coccidioides immitis? Causes?
- Was at one point the only fungal CDC agent
- Found almost exclusivity in Southwestern US.
- Found in desert soil, rodent burrows, mines, remains
- Inhalation of spores.
- Causes Coccidioidomycosis or Valley Fever
What are some characteristics of Histoplamsa Capsulatum? Causes?
- Most common primary fungal pathogen
- Found eastern USA, Africa, Asia
- Found in moist soils, rich in N from bat/bird droppings
- Inhalation of spores.
- Causes Histoplamosis or Spelunker’s Disease.
What are some characteristics of Paracoccidioides brasilienses? Causes?
- found in S mexico and South america
- Rare disease found most in farm workers
- Infection begins as pulmonary condition
- Has steering wheel buds
- Causes Paracoccidioidomycosis, cutaneous ulcer
What are some characteristics of Candidiasis?
- Most common opportunistic fungal infection
- normal microbiota of skin and mucous
- One of few fungi that can be transmitted between people.
What are some key characteristics of Candida albicans? Causes?
- opposite in that Hyphae forms are more pathogenic than yeast forms.
- Most important fungal pathogen in oral cavity
- Causes Thrush, Diaper Rash, Onychoycosis, Ocular Canidiasis.
What is Hypersensitivity, Noninvasive, and Acute invasive pulmonary Aspergillosis?
- Asthma or allergic diseases caused by spores
- Fungi can grow in cavities left by previous case TB
- Death of lung tissue, may present as pneumonia
What are some key characteristics of Cryptococcus neoformans?
- opportunistic fungal infection
- Inhalation of spores found in bird droppings
- Resist phagocytosis by large acidic mucopolysaccharide capsule.
- Predilection for CNS