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M1 Spring Block 1 > Parasitology/Mycology > Flashcards

Flashcards in Parasitology/Mycology Deck (44):
1

Fungal membranes contain ____________ rather than cholesterol.

Ergosterol

2

Fungal cells are surrounded by a rigid ___________ composed of carbohydrate polymers and ___________.

Cell wall; protein
*chitin, α-glucan, β-glucan, α-mannan

3

Most fungi are ___________, require only an organic carbon source, nitrogen source and are _____________.

Free-living
Nonmotile

4

Yeast reproduce by ___________ or __________.

Budding
Fission

5

Some yeast elongate and adhere to one another forming _______________.

Pseudohyphae

6

Hypahe/mycelium are also referred to as _______.

Mold

7

What are 3 types of hyphae?

Nonseptate
Septate uninucleate
Septate multinucleate

8

Blastoconidia, chlamydoconidia, arthroconidia are three types of __________________.

asexual reproductive elements

9

What are two types of conidiospores?

Macroconidia - large, multicelled
Microconidia - small, unicellular

10

Sporangiospores are ___________ spores formed within sacs (sporangia)

Single celled, asexual

11

Fungal infections can cause superficial, ____________, _____________, _____________ and opportunistic infections.

1. cutaneous
2. subcutaneous
3. systemic

12

Hypersensitivity to airborne conidia/spores can lead to ___________________.

Strong allergic reactions

13

Fungal infections can cause superficial, ____________, _____________, _____________ and opportunistic infections.

1. cutaneous
2. subcutaneous
3. systemic

14

Hypersensitivity to airborne conidia/spores can lead to ___________________.

Strong allergic reactions

15

What is a mycotoxin?

Poisonous secondary metabolite produced by fungi.

16

What 4 systems to anti-fungal drugs target?

1. Ergosterol
2. Cell wall synthesis
3. Nucleic acid synthesis
4. Disruption of microtubules

17

What are a few broad classes of anti-fungals?

1. Azoles - imidazole
2. Polyenes - amphotericin
3. Echinocandins
4. Antimetabolites

18

What are possible drawbacks to combination therapy for fungal infections?

1. Action of one reduces the concentration of the target for the second
2. Action of one modifies the target of the second
3. Action of one blocks the accessibility of the second

19

Resistance to antifungal drugs can occur thru which 3 mechanisms?

1. Efflux pumps
2. Target alterations
3. Reduced access to drug targets

20

What are 4 mechanisms of resistance to azoles?

1. Increased expression of efflux pumps
2. Decreased affinity of target
3. Increased expression of target
4. Alternative metabolic pathways leading to the synthesis of ergosterol
5. Use of azoles in agriculture?

21

Are fungi displaying the eagle effect?

Yes

22

What are 4 mechanisms of resistance to azoles?

1. Increased expression of efflux pumps
2. Decreased affinity of target
3. Increased expression of target
4. Alternative metabolic pathways leading to the synthesis of ergosterol
5. Use of azoles in agriculture?

23

Innate immunity is the __________ source to overcome a fungal infection.

Primary. Phagocytes, complement system and PRRs

24

A persistant fungal infection causes T cells to differentiate to ______ CD4+ cells. These T cells activate _____________ which ultimately control the infection.

1. Th1
2. Macrophages

25

What kind of organisms are parasites?

eukaryotic pathogens

26

Endoparasites are divided into _____, unicellular, and ______, multicellular.

protozoan
helminths

27

A ____ host is the host in which the sexual stage of a parasite life cycle (when mating occurs) whereas a _____ host is the host in which asexual reproduction/development occurs.

-definitive
-intermediate

28

For Schistomosoma, ____ are the definitive host and ___ are the intermediate host.

-humans
-snails

29

For malaria, ____ are the definitive host and ____ are the intermediate host.

-mosquitos
-humans

30

The _____ host is not an obligate part of the parasite life cycle. Give an example and explain why most people get really sick if they are this type of host.

incidental/accidental
-ex: toxoplasma
-get sick because parasite not adapted to living in humans, so immune system is active

31

A ____ transmits an infectious form of the parasite to another host species. Give two examples:

-vector
1. snail = schistomosoma
2. mosquito = malaria

32

When do physicians need to think about possible parasites?

1. when patients going to travel abroad
2. returning from overseas
3. patients in endemic areas (rural south)
4. immunocompromised patients (AIDS, steroids, transplant, pregnancy, obesity)

33

Which parasites belong in the protista kingdom? Animalia?

-protists
-helminths

34

Give the common names for these helminths and which type they are: (a) cestoda (b) trematoda (c) nematoda

(a) tapeworms; platyhelminthes
(b) flukes; platyhelminthes
(c) roundworms; nemathelminthes

35

Define an egg vs. a larva vs. a cyst vs a hydatid

egg = product of sexual reproduction; prelarval
larva = immature post-ovum
cyst = dormant stage encysted in host
hyadatid = specialized larvae form of Echinococcus granulosus

36

Tapeworms give off _____ that come off in your stool. They are transmitted via _____. Give an example.

-proglottids
-eggs/larval cysticerci
ex) taenia saginata/solium, diphyllobothrium latum (fish), echinococcus granulosis

37

Flukes of the lungs/liver/blood have ____ intermediate host. They are transmitted by _____. Give an example

-one or more
-invasive/ingestive
ex) schistosoma

38

Taenia solium/saginata:
Definitive host: ____; sheds _____
Int host: _____
Transmission/pathology (2): ________

Definitive host: HUMANS; sheds EGGS/PROGLOTTIDS
Int host: PIGS/HUMANS
Transmission/pathology (2):
(a) ingestion of proglottids causes vomiting/diarrhea/ weight loss
(b) ingestion of eggs causes cysticercosis, which can go to any tissue (lumps in muscle DEADLY in brain)
[T. solium is more common]

39

Diphyllobothrium latum
Definitive host: ____; sheds _____
Int host: _____
Transmission/pathology: ________

-Definitive host: HUMANS; sheds EGGS
-Int host: COPEPOD and FISH
-Transmission/pathology: ingestion when swimming in contaminated water/raw fish; causes B12 deficiency, anemia, neuro symptoms

40

Echinococcosis granulosus (Hydatid Disease)
Definitive host: ____; sheds _____
Int host: _____
Transmission/pathology: ________

-Definitive host: DOGS; sheds EGGS in feces
-Int host: HOOFED ANIMALS/HUMANS
-Transmission/pathology: in rural areas/hunters due to ingestion of eggs from dogs' feces having eaten animal organs; causes lung (alveolar), Hydatid disease (pastoral cycle) = when cysts cause pain/rupture/ANAPHYLAXIS
*NOTES: latent up to 20 years; can be mistaken for tumor; hydatid cysts are usually in liver

41

What are the major differences between Schistosoma mansoni, S. japonicum and S. haematobium.

Infection: RIVERS
SM = colon; Africa, Caribbean, Brazil; lateral spike; in feces
SJ = small intestine; SE Asia; no spike; in feces
SH = bladder; Africa; terminal spike; in bladder
*NOTES: larva invades skin-->Swimmer's Itch; may have rash; may get Katayama syndrome (cytokine storm), diarrhea/liver disease/colon cancer (SJ/SM) or GU problems/blood in urine/bladder cancer (SH)

42

Describe how to tell pinworm, whipworm and Ascarias apart (lumenal nematodes) and how can you tell them apart?

1. Enterobius vermicularis (pinworm) = intestinal; direct person-person egg FO contact; no IM host; NOTES: children, perianal scratching (puritis)/psychological trauma
2. Trichuris trichiuria (whipworm) = only humans; intestine; soil egg FO; rural south; malnutrition, bloody stool
3. Ascaris lumbricoides = intestinal; only human; soil; eggs in stool and egg ingestion; rural south; cough; enters venous circulation then migrates to lungs where coughed up and pooped out eventually; malnutrition, poor mental/physical development; inflammation

43

Describe Hookworms.

Necator americanus; in soil; burrows into skin (NO SHOES!!!; coughed up and goes to intestine; fecal transmission; pruritis between toes, bronchitis, anemia, eggs in stool

44

Describe Strogyloides stercoralis.

larvae penetrates skin; rural south; LARVAE in stool/SPUTUM; have 3 different life cycles and can autoinfect host; greater in immunocompromised patients; cough for autoinfection; rash on buttocks; malabsorption/dysentery;