Fungal classifications and yeast infections

Question 1

Why is fungal taxonomy so complicated?

Answer 1

Because many fungi can reproduce both sexually and asexually and the morphological characteristics of these stages are different.

Question 2

What are the 4 clinical classifications of fungi?

Answer 2

1 - Yeasts
2 - Molds
3 - Dimorphic fungi
4 - Poisonous mushrooms (homobasidiomycetes) –> mycetism

Question 3

How do yeast divide?

Answer 3

By binary fission

Question 4

Why is worrying about chronic infections due to molds nonsensical?

Answer 4

Spores of molds are everywhere, but people don’t just get sick off of them

Question 5

When would someone be likely to be infected or have bad outcomes with spores of molds?

Answer 5

When profoundly immunocompromised or if allergic to spores

Question 6

People that are capable of becoming allergic to a broad amount of allergens

Answer 6

Atopic

Question 7

What is the test to tell if someone is atopic?

Answer 7

A wool sweater is itchy on them

Question 8

What does dimorphic fungi mean?

Answer 8

Can grow as yeasts and as molds, depending on the culture

Question 9

Fungi that can produce higher toxins that can kill you, produce psychoactive effects, or make you very sick.

Answer 9

Homobasidiomycetes

Question 10

What is the meat of the homobasidiomycete mushroom made of?

Answer 10

Densely packed hyphae

Question 11

What is the scientific explanation for fairy rings (i.e. mushrooms growing in a perfect circle)?

Answer 11

Homobasidiomycete at the center, exsporulate in an explosive fashion on a night without wind. The spores will fall equidistantly from the center, and produce the fairy ring.

Question 12

Yeast ____ and divided, while molds form _______.

Answer 12

bud

hyphae

Question 13

Single, unconnected vegetative cells (fungi)

Answer 13

yeasts

Question 14

Grow similarly to bacteria, but are much larger.

Answer 14

Yeasts

Question 15

Fungi that reproduce by budding.

Answer 15

yeasts

Question 16

Fungi that do not sporulate.

Answer 16

yeasts

Question 17

Fungi used for commerical production of alcohol and citric acid and do not usually pose a hazard to laboratory workers.

Answer 17

yeasts

Question 18

How do molds grow?

Answer 18

Grow in a complex mass called a mycelium, composed of tubes called hyphae

Question 19

When hypha filaments are packed densely, the mycelium can appear to be a cohesive tissue. What fungal group has this?

Answer 19

Homobasidiomycetes

Question 20

How do molds reproduce?

Answer 20

form spores

Question 21

Aerial hypha

Answer 21

stolon

Question 22

Fruiting heads = ___________.

Stalk holding up the fruiting heads.

Answer 22

Sporangium/a

sporangiophore

Question 23

Describe how many spores are released from the mycelium.

Answer 23

Released in INCREDIBLE numbers

Question 24

How can spores become a contamination hazard?

Answer 24

Can become airborne and present a contamination hazard in labs working on pathogenic molds

Question 25

Spores are most commonly formed _________ (_________), but can also be produced _________ (_________)

Answer 25

asexually - conidia | sexually - ascospores

Question 26

What is the most common fungal infection (Causative agent)?

Answer 26

Candida albicans

Question 27

Most yeast infections are _________.

Answer 27

endogenous

Question 28

Most yeast infections are endogenous, except for ___________ ____________, which is associated with the excrete of gregarious birds, primarily pigeons?

Answer 28

Cryptococcus neoformans

Question 29

Cryptococcus neoformans is associated with what?

Answer 29

Excreta of gregarious birds

Question 30

What does gregarious bird mean?

Answer 30

Birds that flock together

Question 31

What are predisposing factors to superficial yeast infections?

Answer 31

``` 1 - Wet work - e.g. dishwashers 2 - Pregnancy, oral contraceptives 3 - Diabetes mellitus 4 - Broad spectrym antibiotics 5 - HIV infection, CD4 < 500 6. Dectin-1 (Beta-glucan receptor) deficiency ```

Question 32

What does diabetes predispose you to?

Answer 32

Literally everything

Question 33

What are predisposing factors to deep yeast infections?

Answer 33

``` 1 - Cytotoxic chemotherapy, corticosteroids 2 - Indwelling venous catheters 3 - Broad spectrum antibiotics 4 - Intravenous drug abuse 5 - HIV infection, CD4 < 200 ```

Question 34

Why can safe injection sites be a meme?

Answer 34

because the drugs are not supervised

Question 35

Most common yeast causing infection.

Answer 35

Candida albicans

Question 36

Candida albicans is part of the normal flora where?

Answer 36

oropharynx, vagina, bowel and skin

Question 37

What does Candida albicans cause?

Answer 37

acute and chronic superficial infections of: the skin - diaper rash, balanitis, intertriginous areas nails - paronychia mucous membranes - thrush, vaginitis UTI

Question 38

Candida albicans can cause severe disease in who? What are they?

Answer 38

Immuncompromised patients Esophagitis pyelonephritis sepsis

Question 39

What is balanitis?

Answer 39

superficial infection of the glans of the penis

Question 40

What are intertriginous areas?

Answer 40

skin on skin

Question 41

How would one describe a C. albicans rash?

Answer 41

Contiguous, red inflammed mass with silvery whiteish sheen | the defining feature are the satellite lesions

Question 42

What does thrush look like?

Answer 42

adherent white plaques with erythematous base

Question 43

What kind of odour may you smell with thrush?

Answer 43

freshly baked bread

Question 44

What is the major virulence factor of C. neoformans?

Answer 44

Capsule

Question 45

What is used to screen CSF samples for C. neoformans?

Answer 45

India ink test - stands out in darkfield microscopy | also latex agglutination test for antigens (positive)

Question 46

What can C. neoformans cause?

Answer 46

Diffuse pulmonary infection (usually asymptomatic)/progressive pulmonary disease with abscesses or disseminated disease

Question 47

What are the risk factors for disseminated disease?

Answer 47

HIV, malignancy, corticosteroids

Question 48

What can C. neoformans cause, but very rarely? | What can we use to get rid of it?

Answer 48

Intracerebral mass lesions (cryptococcomata) | oral fluconazole

Question 49

C. neoformans can cause chronic meningitis in AIDS patients, but this meningitis is atypical. How?

Answer 49

will only have mild headache, but can walk around | unlike the usual coma which can occur with normal meningitis