Microbio Week 7 - Mycology (Mini Exam)

Question 1

Study of fungi

Answer 1

Mycology

Question 2

What does fungi include?

Answer 2

Yeast and mold

Question 3

Are fungi prokaryotic or eukaryotic?

Answer 3

Eukaryotic

Question 4

As eukaryotes, what type of environment do fungi require?

Answer 4

Aerobic or anaerobic

Question 5

Are fungi plants?

Answer 5

NO, they don’t produce chlorophyll or energy via photosynthesis

Question 6

Acquire nutrition from dead, decaying organic matter; aid in decomposition and recycling of carbon and nitrogen

Answer 6

Saprophytic

Question 7

What do fungi breakdown in humans? What kind of people does this occur more often in?

Answer 7

Epithelial tissue (and spread into deeper tissue)

*occurs more often in immunocompromised people

Question 8

What types of tissues are useful sources of nutrients for fungi?

Answer 8

Ischemic and necrotic

Question 9

How many fungi are capable of causing infections in humans?

Answer 9

A few hundred

Question 10

Why are fungi important to know clinically?

Answer 10

Can cause serious infections, may be resistant to antifungals

Question 11

In what 3 ways are fungi diverse?

Answer 11

Appearance
Benefit/use
Ability to cause disease

Question 12

How many morphologies can fungi display?

Answer 12

Some only display 1, others display combo

Question 13

What are the clinically important morphological forms of fungi?

Answer 13

Yeast
Mold
Dimorphic fungi (display both yeast and mold forms)

Question 13

Single-celled form of fungi; round or oval-shaped

Answer 13

Yeast

Question 14

How do yeast reproduce?

Answer 14

Budding

Question 15

Unequal asexual outgrowth from parent cell; produces genetically identical cells

Answer 15

Budding

Question 16

What are the 2 routes that yeast can take when buds break off?

Answer 16

1. Form single cell
2. Elongate to become pseudohyphae

Question 17

Chain of connected yeast cells that resemble hyphae, but constrict at the point of connection

Answer 17

Pseudohyphae

(think of a balloon animal)

Question 18

What are 2 examples of yeast?

Answer 18

Candida
Cryptococcus

Question 19

What is the multicellular, filamentous form of fungi?

Answer 19

Mold

Question 20

What can mold filaments exist as?

Answer 20

1. Hyphae
2. Mycelium

Question 21

Individual mold filaments

Answer 21

Hyphae

Question 22

Masses/clusters of mold filaments

Answer 22

Mycelium

Question 23

How does hyphae grow?

Answer 23

Lengthening filament and dividing nucleus

Question 24

What may occur when hyphae grow?

Answer 24

Some branching

Question 25

Cross walls

Answer 25

Septations

Question 26

Mold with septations

Answer 26

Septate hyphae

Question 27

Mold without septations

Answer 27

Aseptate/non-septate hyphae

Question 28

Which type of hyphae in mold? Majority of mold species; hyphae are smaller in diameter

Answer 28

Septate hyphae

Question 29

Which type of hyphae in mold? Mold species of the mucor group; hyphae are larger in diameter

Answer 29

Aseptate/non-septate hyphae

Question 30

What is the branching pattern, presence/absence of septations, and hyphae in mold used for?

Answer 30

Distinguishing mold types

Question 31

Can hyphae have pigment associated with them?

Answer 31

Yes!

Question 32

What are 2 examples of mold?

Answer 32

Aspergillus Mucor

Question 33

What do dimorphic fungi alternate between?

Answer 33

Yeast form and mold form

Question 34

What is the alternating between yeast form and mold form in dimorphic fungi based on?

Answer 34

Environmental conditions Temperature

Question 35

Yeast in the ________, mold in the _________

Answer 35

heat; cold

Question 36

4 examples of dimorphic fungi

Answer 36

Candida Histoplasma Blastomyces Coccidioides

Question 37

Which is present with many nutrients, yeast or mold?

Answer 37

Yeast

Question 38

Which is present with reduced nutrients, yeast or mold?

Answer 38

Mold

Question 39

What makes fungal cells different form other eukaryotic cells? (ON EXAM)

Answer 39

Cell membrane contains ergosterol (instead of cholesterol)

Question 40

What is the primary target of antifungals?

Answer 40

Ergosterol

Question 41

The fungal cell wall is a thick, highly cross-linked layer with multiple long-chain ___________ and ___________ (both stimulate the immune system)

Answer 41

polysaccharides; glycoproteins

Question 42

What is the fungal cell wall similar to?

Answer 42

Gram + cell wall (except no peptidoglycan!!)

Question 43

What are the polysaccharides present in the fungal cell wall? (ON EXAM)

Answer 43

a-glucan B-glucan Chitin

Question 44

What are the glycoproteins present in the fungal cell wall? (ON EXAM)

Answer 44

Mannoproteins

Question 45

Which cells phagocytose fungi for intracellular killing in the innate response?

Answer 45

*Neutrophils Macrophages

Question 46

What environment do fungal pathogens grow in?

Answer 46

Aerobic

Question 47

What do fungi secrete that aid in survival and nutrient acquisition in the host?

Answer 47

Extracellular products (enzymes, mycotoxins, antibiotics)

Question 48

Breakdown complex organic material for use in cells

Answer 48

Enzymes

Question 49

Secreted substances that are toxic to humans and animals when ingested or inhaled

Answer 49

Mycotoxins

Question 50

Produced in nature by some filamentous fungi (molds); may inhibit competing microbes

Answer 50

Antibiotics

Question 51

How do fungi reproduce?

Answer 51

Sexual or asexual reproduction

Question 52

Rapid; results in genetically identical offspring

Answer 52

Asexual reproduction

Question 53

What type of reproduction do most pathogenic fungi seen in the clinical setting undergo?

Answer 53

Asexual reproduction

Question 54

What does asexual reproduction of mold form?

Answer 54

Thick-walled asexual spores from hyphal filaments

Question 55

What conditions do spores form in?

Answer 55

Unfavorable (ex: inadequate nutrients/water)

Question 56

What conditions do spores germinate in?

Answer 56

Favorable

Question 57

What are mold spores resistant to?

Answer 57

Drying

Question 58

What are mold spores NOT resistant to?

Answer 58

Heat

Question 59

Single-celled, smaller mold spores

Answer 59

Microconidia

Question 60

Multi-celled, larger mold spores

Answer 60

Macroconidia

Question 61

Fungal diseases may result from introduction of ______________ fungal spores into body, overgrowth of commensal _________, or exposure to ________ products produced by spores

Answer 61

environmental; flora; toxic

Question 62

Mycoses meaning

Answer 62

Infections

Question 63

Fungal diseases may present in the form of what 3 things?

Answer 63

Allergies Mycotoxin exposure Infections

Question 64

What do fungal spores have which may stimulate allergic reactions and respiratory effects?

Answer 64

Surface antigens

Question 65

What can allergic reactions/respiratory effects be from?

Answer 65

Inhaling mold spores due to growth in moist areas

Question 66

What are 2 ways you could get a mycotoxin exposure?

Answer 66

Ingesting contaminated food Inhaling spores (coated with mycotoxin)

Question 67

What can you get an infection from?

Answer 67

Exposure to fungal spores

Question 68

What are fungal infections typically characterized by?

Answer 68

Anatomic location Epidemiology

Question 69

Where can fungal infections be?

Answer 69

Superficial Subcutaneous Systemic (endemic + opportunistic)

Question 70

Many fungi only cause serious disease in what types of people?

Answer 70

Immunocompromised People with foreign devices

Question 71

Where are superficial fungal infections localized to?

Answer 71

Outermost layers of skin, hair, nails

Question 72

Where are subcutaneous/submucosal infections localized to?

Answer 72

Deeper skin structures Submucosal tissue

Question 73

What are subcutaneous/submucosal infections commonly associated with?

Answer 73

Trauma-related inoculation of spores from soil or vegetation

Question 74

Cause infection in immunocompetent individuals

Answer 74

Endemic

Question 75

Cause infection in immunocompromised individuals

Answer 75

Opportunistic

Question 76

What 2 things can systemic infections be due to?

Answer 76

Commensal fungi that overgrows (candida) Environmental fungi that is inhaled (mucor)

Question 77

T/F: All pathogenic fungi have the ability to be opportunistic

Answer 77

True

Question 78

The greater the degree of immunocompromise, the greater the likelihood of...

Answer 78

Severe infection