Lecture 7 (23) Clinical Mycology

Question 1

ergot alkaloids

Answer 1

• fungi that grows on bread
• causes hallucinations
• salem witch trials

Question 2

aflatoxin

Answer 2

fungi on peanuts

Question 3

stachybotrys

Answer 3

black fungi on walls with lots of moisture

Question 4

what are the differences between the fungal cell and the mammalian cell?

Answer 4

-fungi have a cell wall and have a different membrane composition that includes sterol

Question 5

fxns of the fungi cell wall

Answer 5

1) shape
2) rigidity
3) strength
4) protection from osmotic shock

Question 6

what a huge virulence factor of fungi

Answer 6

the fungal cell wall and it’s carbs and proteins

Question 7

what’s the difference between a human cell membrane and a fungal cell membrane

Answer 7

fungal cell membrane has ergosterol while human cell membrane has cholesterol

Question 8

what are the two classifications of fungi

Answer 8

yeast and mold

Question 9

dimorphic

Answer 9

fungi that can be both yeast and mold

Question 10

how do yeast reproduce?

Answer 10

via budding

Question 11

psudohyphae

Answer 11

false hyphae made by yeast

Question 12

if you look at a mold under the microscope, and there is a circular form with a long tube attached to (looks like spoon) what is it and what fungi is it?

Answer 12

• germ tube

- candida albicans

Question 13

hyphae

Answer 13

long strand of mold

Question 14

mycelium

Answer 14

group of hyphae

Question 15

what are the two categories of mycelium

Answer 15

• vegetative- embedded in the substrate

- aerial- in air

Question 16

septa

Answer 16

tubes from molds that have breaks in them

way to classify septa and aseptate

Question 17

how do molds reproduce

Answer 17

asexually- with conididia (tiny air floating things)

and sexually- via spores

Question 18

chlamydo- aka arthro-

Answer 18

prefixes indicating mold that have conidia that are in the middle of hyphae

Question 19

superficial mycoses-
cutaneous mycoses-
subcutaneous mycoses-

Answer 19

superficial mycoses- mold that infects the outermost layers of the skin and hair
cutaneous mycoses-deep into the epidermis
subcutaneous mycoses-into the dermis, muscle and fascia

Question 20

systemic mycoses

opportunistic mycoses

Answer 20

systemic mycoses- start off as a lung infection and then get into other organs
opportunistic mycoses- usually associated with immunosuppressed indivs

Question 21

what do we have that prevents us from developing a fungal infection?

Answer 21

• skin
• pH
• competition with normal bacterial flora
• epithelial turnover rate =hi
• desiccated nature of the stratum corneum-dead cells on the outside of skin
• mucus membranes

Question 22

what type of immunity is useless against fungi?

Answer 22

-humoral (antibodies)

Question 23

amphotericin B

Answer 23

• polyene

- binds ergosterone on plasma membrane and causes pore to open and massive efflux that causes lysis of the cell

Question 24

polyenes

Answer 24

-bind membrane sterols (ergosterol) and causes fungal lysis

Question 25

azole derivitives

Answer 25

inhibit ergosterol synth

Question 26

nucleoside analogs

Answer 26

inhibit fungi DNA/RNA synth

Question 27

Grisans

Answer 27

• used for fungal infections of scalp

- inhibits microtubules

Question 28

allylamines

Answer 28

inhibit ergosterol synth

Question 29

thiocarbamates

Answer 29

inhibit erosterol synth

Question 30

morpholines

Answer 30

inhibit ergosterol synth

Question 31

echinocandins

Answer 31

• inhibits B glucan synth (cell wall inhibitor)=
• highly selective (b/c we don’t have a cell wall) and useful and limited to a handful of disease causing fungi
• used to treat candida (yeast infection) and aspergillus

Question 32

how are fungi usually diagnosed?

Answer 32

via looks

Question 33

KOH prep

Answer 33

used to look at fungi

use 15% KOH and it dissolves other matter quicker due to fact that fungi have chitin- look at fungi under microscope

Question 34

what do all fungi stain?

Answer 34

gram +

Question 35

chlorazol black and calcofluor white

Answer 35

reveal carbohydrate rich cell wall of fungi

Question 36

gomori methylamine silver

Answer 36

histological stains that enhance detection of fungi

Question 37

if you have a positive india ink stain, what does that indicate

Answer 37

Cryptococcus neoformans

-crypts in india