Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MICROM 460 > Mycology Lecture 2 > Flashcards

Mycology Lecture 2 Flashcards

1
Q

Most common fungal species to cause disease

A

Opportunistic invasive mycoses (esp. in immunocompromised patients)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Examples of opportunistic invasive mycoses

A

Aspergillosis, Candidiasis, Cryptococcosis, Mucormycosis, Pneumocystis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

True or false: Endemic dimorphic mycoses have higher mortality rates than opportunistic invasive mycoses

A

False - OIM has much higher mortality rates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Normal human fungal microbiota is usually characterized as:

A

commensalism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Many fungi live as commensals with humans, including species such as:

A

Candida; Malassezia; Pneumocystis jiroveci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Candida as a normal human commensal is usually found in the ____ ___

A

gastrointestinal tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Malassezia species as normal human commensals are usually found:

A

on the outermost layer of skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Pneumocystis jiroceci as a normal human commensal is usually found in the _____ ___

A

respiratory tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Infection (clinical sense)

A

fungus or immune response to fungus causes damage to host tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

True or false: humans generally are needed for the completion of fungal life cycle

A

False - infections are often accidental encounters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

True or false: person to person/animal to person transmission of mycoses are rare

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are some common themes for causing fungal diseases? (4)

A
  1. exposure
  2. portals of entry (damage to barriers)
  3. immunocompromised state of host
  4. fungal thermotolerance/other fungal attributes that can help them evade immune system and survive in the body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

True or false: fungi grow very quickly

A

False - may not grow quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

True or false: fungi may not move fast in infections

A

True (ex: fungal meningitis may take weeks to months to be diagnosed and to kill host)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True or false: if fungi do not grow quickly in disease, it can be hard to treat and may require life-long treatments

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

True or false: “epidemics” of mycoses are sometimes reported

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where do fungal infections come from?

A

environmental source (yeast or mold) transfers to human host through inhalation, ingestion, traumatic inoculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Traumatic inoculation

A

major disruption of the skin, like through horrible wounds/bone exposed and open to the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Once a fungal infection has been established, it can spread through:

A

dissemination to other organs or via blood (hematogenous)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Portals of entry for fungal infections:

A
  1. skin
  2. inhalation (nasal passages, lungs, sinuses)
  3. mucous membranes (GI and GU tracts, eye)
  4. iatrogenic (catheters)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the three infection classification schemes?

A
  1. invasiveness (superficial, subcutaneous, or deep?)
  2. source of fungi (endogenous or exogenous?)
  3. morphology (yeast/mold/both?)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Name 6 examples of primary pathogens

A
  1. Histoplasma
  2. Coccidioides
  3. Blastomyces
  4. Sporothrix
  5. Paracoccidiodes
  6. Cryptococcus (which is also opportunistic!!)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Key risk factor for a primary pathogen

A

Exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Key risk factor for an opportunistic pathogen

A

Host and/or host response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

True or false: some fungi may produce an allergenic disease

A

True - body recognizes fungus as an allergen; allergic bronchopulmonary aspergillosis (ABPA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Mycotoxicosis

A

another fungal condition marked by specific toxin production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Aspergillus flavus produces a toxin called ____, which is found in and implicated in:

A

Aflatoxin; found in stored grains, corn, peanuts; implicated in liver cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

True or false: ergotism is another fungal condition marked by toxin production and causes Saint Anthony’s Fire

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Why have there been enormous increases in fungal infections?

A
  1. we’ve gotten better at diagnosing

2. (more importantly) large increase in at-risk population and in exposed population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Examples of increased at-risk and exposed populations for mycoses

A
  1. HIV/AIDS pandemic
  2. advances in medical technology (in particular, medical devices and catheters)
  3. climate/habitat change
  4. Urbanization/population growth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

True or false: specific immunodeficiencies will put you at risk for specific fungal infections

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Defects in cellular immunity (T cells) is caused by:

A

HIV/AIDS; solid organ transplant; medications (etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Infections associated with T cell deficiencies:

A

most fungi, including: Candida, Pneumocystis, Cryptococcus, all endemic mycoses, (Aspergillus less common)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Defects in neutrophil number or function caused by:

A

chemotherapy, bone/stem cell transplants**, medications, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Infections associated with defects in neutrophil number or function:

A

Candida, Aspergillus (common), Zygomycetes, several other molds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Methods of lab diagnosis of mycoses

A

histology and direct examination, culture, serology, antigen testing, PCR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Stains used for histology/direct examination

A

GMS “silver stain” and Periodic acid-Schiff (PAS)

other: KOH prep, Calcofluor white to stain chitin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

GMS targets ____ of most fungi. GMS typically stains:

A

carbohydrates; black/brown on light green background

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

PAS stain targets _____ of most fungi. Examples include:

A

polysaccharides; glycogen and glycoproteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

PAS stain color

A

red-pink-purple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Culture usually consists of _____ ____ to prevent ____ ____

A

selective media; bacterial growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Serology tests for ____ ____

A

antibody response (IgM or IgG specifically)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Antigen testing tests for ____ ___. Some examples include:

A

fungal parts (i.e. actual fungal antigens); Aspergillus galactomannan, Cryptococcal antigen, Histoplasma antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Direct exam pros

A

you can see the actual pathologic effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Direct exam cons

A
  • not sensitive
  • difficult to identify species based on appearance alone
  • can’t do susceptibility testing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Culture pros

A

Specific; can do susceptibility testing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Culture cons

A

Sensitivity; time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Antigen testing pros

A

generally faster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Antigen testing varies in ____ and ____

A

sensitivity and specificity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Antigen testing cons

A

No susceptibility testing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

PCR pros

A

specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

PCR cons

A
  • no susceptibilities

- difficult to distinguish between colonization or pathogen

53
Q

Serology pros

A

often specific for fungus

54
Q

Serology cons

A
  • not good in immunocompromised

- may just represent colonization, not clinical disease

55
Q

THM: with opportunistic infections in particular, ___ ____ are critical for treatment/cure.

A

host factors

56
Q

THM True or false: With the best antifungal, the infection can be easily cured

A

False - even with the best one, may never cure an infection if the immune system hasn’t recovered

57
Q

THM: ___, _____, and ___ ___ ___ contribute to risk of fungal infection

A

host; environment; fungus specific factors

58
Q

Cutaneous and subcutaneous mycoses have __ incidence because they are ____ distributed

A

high; globally

59
Q

Cutaneous and subcutaneous mycoses are generally __-___, and can cause ____ ____ and ____

A

non-fatal; significant disfigurement; morbidity

60
Q

What antifungal is usually used to treat superficial/cutaneous infections?

A

Azoles and terbafine (affecting ergosterol synthesis)

61
Q

Malassezia globosa is a _____ ____ and usually infects __ ___ in the skin

A

lipophilic yeast; oil glands

62
Q

What diseases does Malassezia globosa cause?

A
  1. Pityriasis versicolor

2. Seborrhoeic dermatitis (including dandruff)

63
Q

Malassezia globosa incidence (common or rare?)

A

common

64
Q

Hortaea werneckii causes:

A

Tinea nigra

65
Q

White piedra is caused by:

A

Trichosporon sp.

66
Q

Black piedra is caused by:

A

Piedraia hortae

67
Q

Pityriasis versicolor presents as:

A

patches of altered pigmentation

68
Q

Why do Malassezia sp. grow in oily areas in the skin?

A

they can’t synthesize their own fatty acids so they use oils in our oil glands

69
Q

True or false: Pityriasis versicolor may be acquired nosocomially through feeding solutions

A

True

70
Q

Which phyla is Malassezia a part of?

A

Basidiomycetes

71
Q

Describe Malassezia hyphae

A

short, slightly curved septate hyphae; extrudes conidia

72
Q

What fungal species is often referred to as having a “russian doll” structure?

A

Malassezia

73
Q

What can you use to treat Malassezia?

A

Topical or oral azoles

74
Q

Describe the fungus that causes Tinea nigra

A

Ascomycete, dematiaceous mold, dimorphic, septate

75
Q

What does Tinea nigra infection present as?

A

Painless brown or black macule on hands and feet

76
Q

Tinea nigra is most common in:

A

Southern US

77
Q

How can you treat Tinea nigra?

A

dandruff shampoo or topical antifungals

78
Q

Piedra involves what part of the body?

A

the hair

79
Q

True or false: White piedra and black piedra are caused by the same fungus, Trichosporon

A

False - only white piedra is caused by Trichosporon

80
Q

Black piedra presents as:

A

black nodules on hair, usually scalp

81
Q

True or false: Black piedra is caused by a mold with non-septate hyphae

A

False - hyphae are septate

82
Q

Black piedra is usually found in the ____

A

tropics

83
Q

Black piedra treatment

A

cutting hair, oral terbinafine

84
Q

Piedra can disseminate to become _____ in ______ patients.

A

trichosporonosis; immunocompromised

85
Q

Dermatophytes are ___ that infect _____ ___ and invade ___, ___, and ___ of the host

A

molds; keratinous tissue; hair, skin, and nails

86
Q

What is the pathogenesis of dermatophytes?

A

invades the epidermis

87
Q

True or false: dermatophytes often cause deep/disseminated disease in immunocompromised patients

A

False - rare dissemination in both healthy and immunocompromised patients

88
Q

What are the three main genera of dermatophytes?

A
  1. Microsporum
  2. Trichophyton
  3. Epidermophyton
89
Q

True or false: there are different groups of dermatophytes based on the natural reservoir they occupy

A

True (geophilic, zoophilic anthropophilic)

90
Q

Geophilic dermatophytes

A

soil-dwellers, saprophytes, occasional pathogen

91
Q

Zoophilic dermatophytes

A

normal host is animals, occasional human infection

92
Q

Anthropophilic dermatophytes

A

confined to human host; person to person transmission

93
Q

Tinea Capitis

A

infections of the hair shaft, scalp

94
Q

Tinea Barbae

A

infections of the skin and coarse hairs of beards and mustache areas

95
Q

Tinea Corporis

A

infections of glabrous skin (aka ringworm)

96
Q

Tinea Cruris

A

infection of the groin area (aka jock itch)

97
Q

Tinea Pedis

A

infection of foot, interdigital web spaces, soles (also called athlete’s foot)

98
Q

Tinea Unguium

A

infections of nail; aka onychomycosis

99
Q

How do we diagnose dermatophyte diseases?

A
  1. skin scraping (KOH)
  2. microscopy
  3. culture
  4. physical examination
  5. hair perforation test
  6. urease test
100
Q

True or false: with Tinea corporis, there can be associated erythema due to inflammatory response

A

True

101
Q

True or false: it is generally easy to eradicate onychomycosis through use of antifungals

A

False - it can often take months of oral antifungals

102
Q

Trichophyton rubrum is a(n) _____ and spreads primarily via:

A

Ascomycete; person to person

103
Q

True or false: Trichophyton rubrum forms macroconidia, but not microconidia

A

False: they form microconidia

104
Q

Which dermatophyte forms a diffusible red pigment?

A

Trichophyton rubrum

105
Q

Most common worldwide cause of dermatophytoses:

A

Trichophyton rubrum

106
Q

Epidermophyton floccosum is a(n) ____ and spreads via:

A

Ascomycete; person to person

107
Q

Epidermophyton floccosum forms what kind of conidia?

A

Macroconidia

108
Q

Which dermatophyte forms “racquet hyphae”?

A

Epidermophyton floccosum

109
Q

Microsporum canis is a(n) ____ and spreads via:

A

ascomycete; cats and dogs (zoophilic)

110
Q

Microsporum canis conidia

A

macroconidia that are spindle-shaped and thick walled

111
Q

True or false: Microsporum canis rarely forms microconidia

A

True

112
Q

Common cause of tinea corporis

A

Microsporum canis

113
Q

Methods of dermatophytes prevention

A
  1. avoid direct contact with fallen hair/desquamated epithelial cells
  2. avoid contacting fomites like combs, hairbrushes, cats, dogs, other animals
  3. keep high incidence areas dry
  4. maintain personal hygiene and disinfect shared items
114
Q

Subcutaneous mycoses pathophysiology

A

traumatic inoculation

115
Q

True or false: subcutaneous mycoses are often chronic infections that can be locally highly destructive, but usually dissemination doesn’t occur

A

True

116
Q

Sporotrichosis is caused by _____ ____ and is found:

A

Sporothrix schenckii; worldwide in soil and vegetation

117
Q

Sporotrichosis pathophysiology

A

starts as a skin ulcer, can spread to lymph nodes and spread upwards as nodules (nodular lymphangitis)

118
Q

Sporotrichosis diagnosis

A

through culture or histology

119
Q

Sporotrichosis treatment

A

Itraconazole, KI, Amphotericin B if severe

hyperthermia may help

120
Q

True or false: chromoblastomycosis is a cutaneous fungal disease

A

False - subcutaneous

121
Q

Chromoblastomycosis is caused by:

A

traumatic implantation of a dematiaceous yeast-like organism into the skin or subcutaneous tissue

122
Q

True or false: chromoblastomycosis agent grows extremely quickly

A

False - very slowly

123
Q

chromoblastomycosis presents as:

A

warty dermatitis, which can be ulcerated or crusted and have color to it

124
Q

Epidemiology of chromoblastomycosis

A

tropics and subtropics, rural areas

125
Q

Histology of chromoblastomycosis

A

brown-walled, round, non-budding fungal forms; cells with vertical and horizontal divisions, sclerotic bodies that look like copper pennies

126
Q

chromoblastomycosis culture

A

you’d find pigmented fungi

127
Q

Treatment of chromoblastomycosis primarily involves:

A

surgery

128
Q

True or false: itraconazole or terbinafine may be used to treat chromoblastomycosis

A

True (but surgery is usually the easiest to eradicate fungus)

129
Q

Name some examples of opportunistic pathogens

A
  1. Aspergillus
  2. Non-Aspergillus molds (Zygomycetes, Fusarium, Scedosporium)
  3. Candida
  4. Pneumocystis
  5. Cryptococcus

MICROM 460 (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions