Microbiology 8s - Fungal infections Flashcards
name 3 yeasts
Candida
Cryptococcus
Histoplasma (dimorphic i.e. can change between yeast and mould)
name 2 moulds
aspergillus
dermatophytes
stain for candida
periodic acid schiff stain (PAS)
why are patients in ITU prone to candida infections?
lots of lines and candida is good at forming biofilms and colonising prosthetics
pseudohyphae/germ tube = ?
Candida albicans, no other type of candida infection has this
organs infected in systemic candidiasis
spleen + liver
culture medium used in candida
Sabouraud agar - contains antibiotics so kills bacteria which compete with candida
serology done for candida
beta-D-glucan assay
empirical candida management and albicans management
empirical = echinocandins fluconazole = albicans specific
what drug is cryptoccosu resistant to?
Echinocandins
management of crypto coccus
3 weeks amphotericin B +/- flucytosine
where does crypto coccus have a predilection for?
CNS
WHICH species of cyrptococcus seen in immunocompetent people?
Cryptococcus (neoforamns var) gattii (grows in eucalyptus)
diagnostic tests for Cryptococcus
EIA /antigen test, india ink staining
diagnosis of aspergillus
microscopy and looking at the SPORES (not hyphae) to identify the species
stain used for aspergillus
methenamien silver
management of aspergillus
1st line = >6weeks of amphotericin B/ambisome and 2nd line = voriconazole
main etiological agent of tinea pedis and tinea cruris + tinea capitis
tricophyton rubrum
malassezia furfural –> ?
Pityriasis versicolor
antifungals which target the cell membrane
Polyenes e.g. amphotericin B, nystatin and azoles
echinocandins e.g. caspofungin MOA
Inhibit cell wall synthesis
anti fungals which target DNA/RNA synthesis
Flucytosine
azoles MOA
Inhibit ergosterol production
voriconazole useful against which fungi?
Aspergillus
