Flashcards in Microbiology 16 - Fungal infections Deck (30)
What is the main conponent of fungal cell walls?
What is the main component of fungal cell membranes?
What is the reproductive method of yeats?
Recall 3 examples of yeasts that are clinically important
What are moulds?
Give 2 examples of moulds that are clinically important
Recall the empiric treatment for oral, vulvovaginal and cutaneous candida infection
Vulvovaginal and cutaneous: co-trimoxazole, but if oral treatment is needed then use fluconazole
Recall the principles of candidaemia management
1. Look for source and signs of dissemination:
- Serology for B-D-glucan
2. Antifungals for at least 2/52 from date of first negative blood culture - repeat BCs every 48 hours
Recall the different types of cryptococcus, and which of these infect immunocompetent vs immunocompromised hosts
Serotypes A and D = cryptococcus neoformans (immunocompromised hosts)
Serotypes B and C = cryptococcus gatti (immunocompetent hosts)
Which type of cryptococcus can cause meningitis?
What ink can be used to stain for cryptococcus?
How should cryptococcus infection be managed?
1. Induction: 2/52 of amphotericin B + flucytosine
2. Consolidation: 8/52 of high dose fluconazole
3. Maintenance: 1 year low-dose fluconazole
Which type of aspergillus disease is an allergic disease?
How does aspergillus appear under the microscope?
What parts of the body can be infected by aspergillus?
Pre-formed cavities (eg. by TB) - so treated pulmonary TB may be in the history
What is a galactomannan assay used for?
Why is pneumocystis jirovecii an unusual fungus?
No ergosterol wall
What is the typical history for PCP pneumonia?
Desaturating on exertion
What are the clinical features of mycormycoses?
Orbital/facial cellulitis with discharge of black pus from nose/ palate
How are mycormycoses managed?
LONG duration of ambisone (amphotericin B)
Recall an example of a dermatophyte
Where does tinea cruris infect?
How is tinea diagnosed?
Often clinically, but can be confirmed via skin scrapings for MC&S
Recall 4 classes of antifungal
Recall the side effect profile of each class of antifungal
Azoles - abnormal LFTs
PolyeNes - Nephrotoxicity
Echinocandins - relatively innocuous
Pyrimidine analogues - blood disorders
What is the mechanism of action of azoles?
Inhibit ergosterol synthesis
What is the mechanism of action of polyenes?
Bind sterols in membranes to create leakage of electrolytes
Give 2 examples of polyene medications
Which 2 types of fungus are echinocandins particularly useful for?