fungi infections Flashcards
1
Q
presentation of fungi infections
A
- common, minor, skin and mucosal infections
- also some rare deep tissue infections
2
Q
difference between yeast and mould
A
yeast
- round/oval shape
- single cell
- reproduce by budding
- e.g. candida albicans, cryptococcus neoforms
mould
- tubular hyphae shape
- multi cells
- reproduce by spores
- eg. dermatophytes, aspergillus species
3
Q
candida albicans
A
- commensal of mouth, gut, vagina
- overgrowth caused by antibiotics, immune suppression, hormonal effects etc
causes: vaginal or oral thrush, nappy rash, candidiasis
4
Q
diagnosis of candida albicans
A
- seen as black yeast with pseudohyphae on gram stain
- grows well on blood agar
5
Q
treatment for candida albicans
A
- usually topical sometimes oral
- nystatin suspension or pastilles
- amphotericin B pastilles
- azalea pessaries or cream
6
Q
source of Cryptococcus neoformans
A
- pigeon faeces, mulch underneath gum trees
7
Q
cryptococcus neoformans disease
A
- inhalation of aerosolised fungus from environment -> pulmonary infection
- can spread via blood to CSF -> meningitis
- chronic lymphocytic meningitis
8
Q
diagnosis of cryptococcus neoformans
A
- lumbar puncture
- colour change with ELISA cryptococcal antigen
- brown colonised on bird seed agar
9
Q
dermatophytes
- diagnosis
- treatment
A
- cause ringworm
- never are invasive
- human and animal hosts
diagnosis
- culture and microscopy
treatment
- skin = topical azole
- nails = oral agent e.g. terbinafine
10
Q
aspergillus fumigates
A
- spore-bearing branching mould
- widespread in rotting vegetation
- rare cause of severe disease in neutropenic patients
- cause cavitating necrotising pneumonia
11
Q
anti-fungal drugs
A
amphotericin B
- binds to ergosterol disrupting membrane leading to death
azoles
- inhibit ergosterol synthesis
- oral
- relatively non-toxic
