Introduction to Fungi and Superficial Mycoses Flashcards

1
Q

how do fungi reproduce?

A

sexual and asexual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

are molds multicellular or unicellular?

A

multicellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what does it mean that a fungus is monomorphic?

A

one form in environment and host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does it mean that a fungus is dimorphic?

A

two forms
triggered by temperature, CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how long does fungus culture/growth in culture take?

A

days to weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the five Ds of fungal diseases?

A

debilitating
destructive
difficult to diagnose
difficult to treat
do not have effective vaccines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

fungal diseases are ________________________, but not always

A

often opportunistic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the host defenses against fungal infections?

A

intact skin and mucosal surfaces
low pH
antimicrobials
normal flora
mucus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does Dermatophytosis (ringworm) infect?

A

keratinized tissues: epidermis, hair, feather, claws

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the virulence factors of Dermatophytosis (ringworm)?

A

enzymes: keratinases digest keratin in skin, hair, nails, horn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

are Dermatophytes zoonotic?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the components of fungi cell walls?

A

chitin
ergosterol
beta-glucagon
cellulose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the two morphologic forms of fungi?

A

molds
yeast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how do yeasts reproduce sexually?

A

conjugation
rare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are hyphae?

A

mycelia
branching filaments: septate branches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how do fungal cell walls stain with periodic acid schiff’s stain?

17
Q

how do fungi stain with grocott’s methenamine silver stain?

18
Q

what are some monomorphic fungi?

A

Aspergillus spp: mold
Malassezia spp: yeast

19
Q

what is one dimorphic fungus?

A

Coccidioides immitis

20
Q

what types of diseases can dimorphic fungi cause?

21
Q

what is a polymorphic fungus?

A

Candida albicans

22
Q

what are the steps of germination for a mold?

A

spore swelling and increase in metabolic activity
formation of tubular projection
long growth leads to septa
formation of lateral branches
formation of mycelium (interlacing hyphae network)

23
Q

how are patients usually exposed to fungi?

A

environmental

24
Q

what host factors increase disease risk and severity?

A

prolonged antibiotics
immune compromise
very young/old
persistent moisture
co-morbidities

25
what pathogen factors increase disease risk and severity?
dose virulence factors ability to invade or evade
26
what is a fungi that infects nails and produces keratinocytes?
Onchomycosis
27
what virulence factors help fungi survive inside the host?
capsule and cell wall: resist phagocytosis and low pH enzymes: catalases, proteases iron binding proteins
28
are dermatophytoses primary pathogens or opportunistic?
primary pathogens
29
what is the most common cause of animal candidiasis?
Candida albicans
30
how do Candida spp lead to systemic spread?
vascular invasion by hyphae or pseudohyphae
31
are Malassezia spp monomorphic, dimorphic, or polymorphic?
monomorphic
32
what diseases do Malassezia spp cause?
otitis externa dermatitis
33
what opportunistic conditions lead to Malassezia spp causing disease?
moist skin ear canal
34
what are some associated conditions of Malassezia spp?
allergy seborrheic dermatitis bacterial dermatitis
35
what are the virulence factors of Malassezia spp?
lipases zymogens proteases
36
is ringworm a commensal?
no
37
how can you diagnose ringworm?
collect plucked hair and deep skin scraping: cytology, wood's lamp, histology
38
are Dermatophytes zoonotic?
yes