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Flashcards in Mycology (complete) Deck (80):
1

What are the two distinctive features of fungi

Chitin in the cell walls
Ergosterol in the membranes

2

What is Dimorphism of fungi

their form changes with temperature
Molds at 26 degrees Celcius
Yeast at 37 degrees celcius

3

What are mycoses difficult diseases to diagnose and treat

the signs of their diseases are missed or misinterpreted
there are few antifungal agents, and fungi are often resistant to them

4

Are many mycoses contagious

nope, with the exception of dermatophytes, fungi found on the skin

5

How are mycoses generally acquired

inhalation, trauma, or ingestion

6

how does fungal dimorphism play into a fungus' pathogenicity

in the environment, at lower temperatures, they have mycelia composed of hyphae
in the body, warmer temperatures, they exist as yeasts

7

Why does it matter that fungi are yeasts when inside the body

because now they are invasive due to the enzymes and proteins they produce to survive in the body

8

What are the three categories of fungal diseases

1. fungal infections
2. Toxicoses
3. Allergies

9

What is a fungal infection

the most common fungal disease, caused by a true pathogen, or an opportunistic one, in the body

10

What is a Toxicoses

When you eat poisonous mushrooms

11

When do you get fungal allergies

most often results when inhalation of fungal spores occurs

12

What are the four locations you can get a fungal infection

1. superficial - on the skin - no inflammation
2. cutaneus - on the skin, hair or nails
3. subcutaneos - below skin - traumatic injury
4. deep or systemic - in organs or bone (difficult to diagnose and treat)

13

What are the 4 systemic pathogenic, dimorphic fungi

1. Blastomyces
2. coccidioides
3. Histoplasma
4. paracoccidioides

14

How are the 4 systemic pathogens introduced into the body

inhalation

15

where do the systemic fungal infections begin, and how do they spread

they begin in the lungs and spread via the blood to the rest of the body

16

besides blastomyces, coccidioides, histoplasma, and paracoccidioides. how do other fungal infections occur

by opportunistic fungi, that are often commensals, that take advantage of weaknesses in a host's defense

17

What makes you most likely to get an opportunistic fungal infection

having a compromised immune system

18

What is the causative agent of blastomycosis

blastomyces dermatitidis

19

where is blastomycosis common

south east US and canada

20

how does one contract blastomycosis

inhalation of dust with the fungal spores being carried into the lungs

21

what is the most common type of blastomycosis

pulmonary blastomycosis

22

What are the problems associated with pulmonary blastomycosis

pulmonary lesions that begin asymptomatic
granulomatus reaction with marked fibrosis
can become chronic pneumonia

23

Where can pulmonary blastomycosis disseminate to

the skin, bone, or in males the prostate

24

what can blastomycosis cause in AIDS patients

meningitis

25

how is blastomycosis treated

amphotercin B

26

What is the common name for coccidioidomycosis

valley fever

27

where do you find coccidiodomycosis

in the southwestern US, in desert soil, mines, rodent burrows, and archealogical remains

28

how does a human contract coccidiodomycosis

inhalation of dust that carries the arthrospores (asexual spores) into the lungs

29

what is the causitive agent of valley fever

coccidioides immitis

30

what happens to the coccidioides immitis arthrospores once in the lungs

they germinate into spherules that in turn produce more spores that are released into surrounding tissue

31

Where do most coccidioides infections occur

in the lungs, pulmonary conditions

32

what happens to healthy individuals who get a coccidioides infection

the infections resolve on their own and require no treatment

33

What is the preferred drug against coccidioides infections

amphotercin B

34

what is another name for spelunkers disease

histoplasmosis

35

what is the causitive agent of spelunkers disease

histoplasma capsulatum

36

Where can you find histoplasma capsulatum

mostly Eastern US, some in Africa and Asia

37

what is the most common route of infection of histoplasma capsulatum

inhalation of spores into lungs

38

what happens once histoplasma capsulatum gets into the lungs

it first attacks alveolar macrophages, then it is dispursed beyond the lungs via blood and lymph

39

how problematic are most histoplasma capsulatum infections

they are usually asymptomatic and resolve without damage

40

clinical histoplasmosis can result in one of four diseases what are they

chronic pulmonary histoplasmosis
chronic cutaneous histoplasmosis
systemic histoplasmosis
ocular histoplasmosis

41

what is the preferred drug against histoplasmosis

Amphotercin B

42

What disease is the infection pattern of chronic pulmonary histoplasmosis similar to

TB (granulomas and latent reactivation)

43

What is the causitive agent of paracoccidiodomycosis

paracoccidioides brasiliensis

44

Where is paracoccidiodomycosis typically found

Mexico and south america

45

who is most likely to contract paracoccidiodomycosis

farm workers

46

what other fungal infections are similar to paracoccidiodomycosis

blastomycosis and coccidioidomycosis

47

What is the drug of choice for paracoccidiodomycosis

amphotercin B or Ketoconazole

48

What is the most common causitive agent of candidiasis

candida albicans

49

What is the most common opportunistic fungal infection

candidiasis

50

are candida part of the natural microbiota, if yes, where

they are common microbiota of the skin and mucus membranes

51

can candida be transmitted between individuals

yes

52

how does the dimorphism of candida differ from other fungi

the yeast is the commensal form, the fliamentous forms are more pathogenic

53

What is the most important fungal pathogen in the oral cavity

candida

54

What are four clinical manifestations of candida

Thrush
diaper rash
onychomycosis
ocular candidiasis

55

What is used to treat candidiasis

polyenes (nystatin, amphotercin)
axoles (miconazole, clotrimazole)
DNA analogues (flucytosine)

56

What is the main causitive agent in cryptococcis

cryptococcus neoformans

57

where do the spores (that cause disease when inhaled) of cryptococcus neoformans come from

bird droppings

58

What characteristics of cryptococcus neoformans enhance its pathogenicity

1. its ability to resist phagocytosis which is due to a large acidic mucopolysaccharide capsule
2. predilection for the CNS

59

What are the four diseases that can come from cryptococcus infection

1. primary pulmonary cryptococcus
2. cryptococcal meningitis
3. cryptococcoma
4. cutaneus cryptococcosis

60

What are the possible outcomes of primary pulmonary cryptococcus

it can be asymptomatic, mild pneumonia, or develop into chronic pneumonia

61

what is the most common disease that comes from a cryptococcal infection

cryptococcal meningitis (caused by dissemination of the fungus to the CNS)

62

What is cryptococcoma?

a rare condition in which solid fungal masses form in cerebral hemispheres or the cerebellum

63

what is the treatment for cryptococcus infection

synergistic combination of amphotercin B and 5-flurocytosine

64

What did pneumocystis jirovenci used to be called

P. carnii

65

pneumocystis jirovenci is a normal member of the human microbiota, when can it become problematic

in AIDS patients, immunosuppressed patients

66

pneumocystis jirovenci can lead to pneumonia, the presence of the disease is almost diagnostic of _____

AIDS

67

What is used to treat pneumocystis jirovenci and why

antiprotozoan drugs (septra), because of its similarities to protozoa

68

What are the most commonly reported fungal diseases

superficial, cutaneous and subcutaneous mycoses

69

how are superficial, cutaneous and subcutaneous mycoses acquired

person-to person contact or environmental exposure

70

how serious are superficial, cutaneous and subcutaneous mycoses

they aren't usually life threatening, but can be chronic or reccuring

71

do superficial mycoses illicit an immune response

not usually

72

What is the difference between dermatophytoses and dermatomycoses

dermatophytoses are caused by epidermophyton, microsporum, or trichophyton
dermatomycoses are caused by any other fungi

73

what are dermatophytoses

fungal infections of the skin or nails caused by dermatophytes

74

what were dermatophyte infections formerly known as

ringworms

75

What do dermatophytes use as a nutrient source, and what does that mean for where they reside

they use keratin as a nutrient source, and thus only colonize dead tissue

76

can dermatophytes damage living tissues

yes by provoking a cell-mediated immune response

77

what are the three genera of ascomycetes that cause most dermatophytoses

trichophyton
microsporum
epidermophyton fluccosum

78

What is the treatment for dermatophytoses

topical antifungal agents

79

What are these common dermatophytoses
tinea pedis
tinea cruris
tinea unguinum
tinea corporis
tinea capitis

tinea pedis = athletes foot
tinea cruris = jock itch
tinea unguinum = nails
tinea corporis = body
tinea capitis = scalp with hair loss

80

What is immunity to fungi dependent on

activated macrophages