fungi

Question 1

gen fungi traits

Answer 1

eukaryotic
strict aerobes (except brewer/baker yeast)
defined nuc.
cell membrane has ergosterol instead of cholesterol
cell walls have chitin, mannan, and glucan

Question 2

gen. traits of yeasts/molds

Answer 2

both can cause disease in humans
yeast: unicellular, bud/use binary fission, have pseudomycelium
mold - filamentous w/ hyphae

Question 3

a hyphal mass is called ______, when it has cross walls it’s called ______ without cross walls it’s _______

Answer 3

mycelium - hyphal mass
septate - w/ cross walls
coenocytic - w/o cross walls

Question 4

2 fungal encounter mechanisms

Answer 4

1. incidental environmental contact - high inoculum or immunosuppression needed
2. normal human flora - esp yeasts, cause infection in immunocomp.

Question 5

bodily fungi responses

Answer 5

skin/natural barriers: low pH, desiccation, ep. turnover, microflora and fatty a’s
infections contained by neutrophil phagocytosis
infections eliminated by t cell mediated immunity

Question 6

diff btwn endemic and opportunistic funge?!?

Answer 6

endemic: restricted geographically, true pathogens result in systemic infections in healthy people
opportunistic: fungi aren’t true pathogens, cause systemic infect. in immunocompromised patients

Question 7

endemic fungal diseases

Answer 7

histoplasmosis
blastomycosis
coccidiodomycosis

Question 8

histoplasmosis traits

Answer 8

geographically bound to mid-southeastern US
soil organism
have spores get inhaled then transform to yeast phase once they pass mucosal barriers

Question 9

histoplasmosis spreads through the _____. causes a _________ system infection and avoids phagocytosis by ______

Answer 9

lymph
reticuloendothelial
modiffying pH and removing growth factors of phagocytic cell

Question 10

extensive exposure to histoplasmosis can result in ______. the body eradicates it via ________

Answer 10

pneumonia

T lymphocytes

Question 11

blastomycosis region and environment

Answer 11

mississippi river valley/SE USin soil/decaying wood

Question 12

bastomyces’ conidia (spores and filaments) enter through _____ and transform into _________ with _________ buds. and are dealt with by ________

Answer 12

inhalation
thick walled yeasts
single, broad based buds
phagocytosis

Question 13

how is Blastomyosis is similar to histoplasmosis?

Answer 13

presents as pneumonia and skin lesions (like disseminated histoplasmosis)
controlled by cell-mediated immunity
organism can remain viable for a long time

Question 14

coccidiodomcosis habitat

Answer 14

burrows of desert animals

in southwestern US

Question 15

how do coccidiodes enter?

Answer 15

inhaled,
unlike histo/blasto transform into spherules filled w/ endospores
also unlike histo/blasto transformation isn’t temp dependant
spherules resist phagocytosis

Question 16

coccidiodes disease characteristics

Answer 16

targets lunges/but can spread to pulmonary infection

causes desert rheumatism and skin nodules from host response

Question 17

disseminated coccidiodomycosis can lead to

Answer 17

chronic meningitis that needs life time antifungal therapy

Question 18

how do you treat coccidiodomycosis?!?

Answer 18

polyenes - lipophilic bind to ergosterol

Azoles - stops ergosterol synth, esp itraconazole

Question 19

what leads to recurrent/disseminated infections with endemic fungi?

Answer 19

granulomas

Question 20

opportunistic mycoses diseases

Answer 20

candidiasis
cryptococcosis
aspergillosis
mucormycosis
pneumocytosis

Question 21

candida environment

Answer 21

endogenous (microflora)

in GI/repro tracts

Question 22

what’s special about kidney structure

Answer 22

has dimorphism; can have mycelial form or yeast form

Question 23

candida infection locations and severity

Answer 23

can be mucosal, cutaneous, or systemic and all can be life threatening

Question 24

candidiasis can present itself as…

Answer 24

thrush- thick white lesions or mucosa
intertriginous candidiasis - diaper rash
disseminated infection

Question 25

traits of cryptococcus neoformans

Answer 25

yeast found in soil
produces lg. capsule in tissues but not environment
grows well @ body T

Question 26

cryptococcosis infection traits ?!?

Answer 26

in immunocompromised
can cause pulmonary infection - pneumonia
disseminated - can enter CNS and cause meningitis and brain abscesses

Question 27

virulence factors of cryptococcosis

Answer 27

capsule = prevents phagocytosis

melanin - enhances cell wall

Question 28

fungi that cause pulmonary infection

Answer 28

cryptococcus
aspergillus
mucormycosis
pneumocystis

Question 29

aspergillus environment and entry?!?

Answer 29

ubiquitus

inhaled and turn into hyphae that invade thru blood vessel walls

Question 30

aspergillus damage

Answer 30

causes abscesses and necrotic skin lesions
can cause allery/asthma
can cause pneumonia
has toxic metabollitic products- alphatoxins and phospholipase

Question 31

mucormycosis infection is similar to_______ and has two clinical manifestations….

Answer 31

aspergillus

1. rhinocerebral form- diabetic specific (attacks face)
2. disseminated mucormycosis - pulmonary lesions

Question 32

not much is known about pneumocystis but it’s restricted to ______ and causes ______

Answer 32

lungs

pneumonia

Question 33

most common fungal infections in humans are clinical diseases called ______ which are a type of _______

Answer 33

tineas (ring worm/athletes foot) - type of dermatophyte

Question 34

examples of superficial mycoses

Answer 34

seborrheic dermatitis- greasy scales in facial hair/scalp

tinea versicolor - pigmented skin patches

Question 35

dermatophyte risk factor and requirements?!?

Answer 35

hanging out with kids, need to have skin trauma and continuous moist conditions

Question 36

what’s common btwn subcutaneous and superficial fungal infections?

Answer 36

locallized

need immunocompromised person

Question 37

examples of antifungals are______ and _____

Answer 37

allylamines - block ergosterol synth

echinocandins - inhibit beta glucan synth