Medically important fungi Flashcards
What are fungal diseases known as?
Mycoses
What are the 5 types of fungal infections?
- Superficial
- Cutaneous
- Subcutaneous
- Systemic
- Opportunistic
- Superficial myscoses infect:
- How do they typically infect?
- Skin and hair
- Direct contact
Malassezia furfur
- Where does it live?
- What disease does it cause?
- Lives in epithelial cells
- Pityriasis versicolor
What are the symptoms of pityriasis versicolor?
Hypopigmentation
Destroys malanocytes (pigment cells)
Trichophyton rubrum
What diseases does it cause?
What part of the body does it infect?
How is it contracted?
- Tinea diseases: Ringworm, jock itch, athlete’s foot
- Infect deeper Keratinized layers
- Direct contact
- How do subcutaneous fungi typically infect?
- What type of disease are they?
Direct contact through traumatized skin
Chronic condition
Sporothrix schenckii
- What disease does it cause?
- Where does it travel throughout the body?
- Sporotrichosis (rose gardener’s disease)
- Travels in lymphatic system
What are the signs of sporotrichosis?
- Makes hard nodules
- Become necrotic
What are systemic mycoses?
- In what form do they present themselves?
- How are they acquired?
Found in multiple parts of body
- Usually dimorphic (hyphae to yeast)
- Usually infect by inhalation of spores
Histoplasma capsulatum
What disease does it cause?
Where does it grow?
- Histoplasmosis
- Grows in lung macrophages then goes systemic
What are the signs of histoplasmosis?
Lesions of brain, intestine, heart
Cryptococcus neofromans
- What disease does it cause?
- Where is it typically found?
- How does it infect?
- Cryptococcosis
- Found in bird droppings
- Inhaled then escapes to blood
What are the signs of cryptococcosis?
- Meningitis
- tumor-like masses of brain
How do opportunistic mycoses infect?
Part of normal flora
Take advantage when person is immunocompromised
Aspergillus
What disease does it cause?
How does it form in the body?
- Pulmonary aspergillosis
- Colonies form in lungs then spread to organs
What are the signs of aspergillosis?
Aspergillomas
Fungal balls in lungs
Candida
What is the shape of the fungus?
What diseases does it cause?
- Change from yeast to hyphae
- Candidiasis (multiple types)
What do these types of Candidiasis cause:
- Mucosal candidiasis
- Cutaneous candidiasis
- Thrush- Infection of mouth
- Rash where skin folds
When do Vaginal candidiasis typically infect?
After disruption of normal lactobacillus
Pneumocysria jiroveci
- When does it occur?
- How does it infect?
- What does it do?
- Only in immunocompromised patients
- Inhaled into lungs
- Fills alveoli with exudate (aspyxiation)
What are the methods (3) for antifungals that target plasma membrane?
- Disrupt plasma membrane (highly toxic for humans)
- Disrupt ergosterol synthesis
- Disrupt ergosterol enzymes
What types of infections do these antifungals treat:
- Disrupt ergosterol synthesis
- Disrupt ergosterol enzymes
Synthesis= Systemic/local infections
Enzymes= topical infections
What type of infection do these antifungals treat?
- cell division
- Nucleic acid synthesis
- Cell division= Skin/nail infections
- Nucleic acid synthesis= Systemic infections
How do antifungals that target the cell wall work?
Block polysaccharide synthesis
