Fungal pathogens Flashcards
Which fungus (genus and species) causes pityriasis versicolor?
Malassezia furfur
Which fungi cause dermatophytosis (tinea)?
- Trichophyton
- Microsporum
- Epidermophyton floccosum
Which fungi cause candidiasis?
- Candida albicans
- Candida glabrata
Which fungus (genus and species) causes sporotrichosis?
Sporothrix schenckii
Describe pityriasis versicolor
- pale flaky patches on trunk, neck, arms
- pink/coppery colour on pale skin, lighter colour on dark skin
What is the common name for dermatophytosis?
Tinea, Ringworm
What is tinea circinata?
Classical lesion of tinea. Annular lesions with dry scaly skin in the centre. Slightly raised, inflamed, spreading margin
What is the common name for onychomycosis = tinea unguium?
Fungal nail infection
What kind of candidiasis is Candida glabrata likely to cause?
Vaginal candidiasis
Describe eumycotic mycetoma (maduromycosis) (not in Lecture Outcomes)
- ‘Madura foot’
- subcutaneous mycoses
- pus, presence of ‘grains’ (tightly clumped colonies of microbes)
- subcutaneous swelling over months to years, to deeper tissues
- destroys muscle, fascia, tendons, bones
Describe chromoblastomycosis (not in Lecture Outcomes)
- initial lesion - small elevated itchy patch
- new patches over next months
- pseudoepitheliomatous hyperplasia
- huge cauliflower-like masses
Describe phaeohyphomycosis (not Lecture Outcomes)
- one form infects the nasal sinuses
- another form infects the brain
- cyst-like lesions
- warty (verrucous) in the immunocompromised
- (Exophiala jeanselmei, Wangiella dermatitidis)
Describe sporotrichosis
- more likely in Western Australia
- subcutaneous mycoses
- inoculation –> nodular lesion –> chronic ulcer
- may spread up regional lymphatic channels, suppurative abscesses, sinus tracts
- can be caused by other fungi, Nocardia brasiliensis (Gram +ve rod), Mycobacterium marinum
- hence difficult to treat empirically
What mycoses does Aspergillus cause?
- Aspergillosis (opportunistic)
- Acute bronchopulmonary
- Aspergilloma (fungus ball)
- Invasive pulmonary aspergillosis (necrotising pneumonia, septic emboli)
- Disseminated aspergillosis
- Aspergillosis of paranasal sinuses
- Cutaneous aspergillosis
What is hyalohyphomycosis? (not in Lecture Outcomes)
- mycotic keratitis - corneal infection
- onychomycosis - nail infection
- skin infections (e.g. cellulitis, mycetoma)
- fungaemia and disseminated infection
- caused by hyaline hyphomycetes
