Fungal Infections Mycology Flashcards
what is fungi
uni or multicellular organisms
is fungi aerobic or anaerobic
aerobic eukaryotes
do fungi have a defined or undefined nuclei
defined nuclei
what are the cell walls of fungi made up of
carbohydrate and chitin
ergosterol in plasma membrane
are fungi saprophytic or parasitic
can be both
how do fungi reproduce
sexual or asexual reproduction
asexual spores by mitosis –> infectious forms of hyphal fungi
what is the importance of fungi in veterinary medicine
- allergy (fungal spores)
- cutaneous and superficial mucous membranes (dermatophytes, melessezia, candida infection)
- subcutaneous (sporotrichosis)
- systemic –> primary pathogens (histoplasma), opportunistic pathogens (aspergillus)
- toxins (mycotoxins)
how is fungi diagnosed
laboratory diagnosis
clinical specimens –> skin, hair, nails, swabs from mucous membranes, blood etc
what are the methods of laboratory diagnosis
- direct microscopy: skin, hair, nails, KOH preps, calcofluor white, gram stain on colonies, giemsa
- culture: sabarauds dextrose agar, chromagar, specialized agars, days or weeks –> identification by morphology of hyphae, production of spores, PCR, histology of tissue in invasive disease
what is yeasts
unicellular organisms that reproduce by budding
grow on skin, mucous surfaces and in the body
what are moulds
multicellular organisms that produce hyphae and myeclium and spores (dematophytes –> hyphae grow in skin, hair and nails
what are dimorphic fungi
organisms that can produce both hyphae and yeast like forms
hyphae in environment (+ spores) and yeasts in the infected host –> geographically restricted
how do yeasts grow
by division
budding
binary fission
somtimes the daughter cells may not detach themselves –> result is pseudohyphae (pseudo and true hyphae –> Candida albicans)
what are species of yeasts
candida
malassezia
cryptococcus
is candida gram + or -
gram positive
what are the shape of candida
oval cells
3-6 micromilimeters
what do candida form
germ tubes
chlamydospores
what do candida grow on in lab
37C on sabouraud’s dextrose agar/chromogenic agar
what do candida look like in culture
creamy white colonies
what species is this
candida
what is candida albicans in cattle
causes mycotic abortion
rumenal infections
mastitis
what does candida albicans in pigs
dermatitis
what does candida albicans in dogs cause
chronic enteritis and dermatitis
vaginitis/vulvitis in diabetes
what does candida albicans in birds cause
crop infections, enteritis
what does candida albicans in man cause
mucosal and systemic infections
what is malassezia
bottle shaped
malassezia pachydermatis
what does malassezia grow on
sabouraud’s dextrose agar at 37C
what does malassezia cause
ottis externa
dermatitis
what species is this
malassezia
what is cryptococcus
C. neoformans
C. grubii
C. gattii
what infections does cryptococcus cause
opportunistic infections
defective cell mediated immunity
meningitis
nasal cavity of cats with chronic rhinitis
nasal, cutaneous, neural and ocular disease in cats
what species is this
cryptococcus
what are filamentous hyphal fungi (moulds)
multicellular, multinucleate
what is the basic unit of moulds
hyphae, a long filament
hyphae branch and cross link to form a mat (mycelium)
where does growth occur in filamentous hyphal fungi
growth occurs at hyphal tip
hyphae may be divided by cross-walls (septa) into uninuclear units