L22: Introduction to Human Fungal Infections

Question 1

Most fungal pathogens are NOT communicable, except….

Answer 1

Dermatophytes

Question 2

True or False: Fungi are mostly opportunistic

Answer 2

True

Question 3

True or False: Superficial mycoses are infections of the superficial surfaces of skin (e.g stratum corneum)
and hair. They do NOT involve tissue invasion or inflammation.

Answer 3

True

Question 4

Tinea (pityriasis) versicolor is an example of a ___ mycoses.

Which etiological agent is responsible for causing it?
A. E. coli
B. M. furfur
C. Histoplasma
D. Coccidioides

Answer 4

Superficial ; B.) M. furfur

Question 5

True or False: Tinea versicolor is lipophobic and contagious

Answer 5

False - it is lipoPHILIC and NOT contagious

Question 6

True or False: Tinea versicolor arises due to overgrowth of normal flora

Answer 6

True

Question 7

How can you diagnose T. versicolor using Wood’s Lamp?

Answer 7

Hyper-pigmentation
- Lesions will fluoresce
- YELLOW

Hypo-pigmentation

Question 8

Which of the following skin conditions reveals yeast that has a “spaghetti and meatballs” appearance?

Answer 8

Tinea Versicolor

Question 9

Answer 9

Question 10

What are the two big groups of Cutaneous Mycoses known as?

Answer 10

1. Dermatophyoses: Molds
   - Microsporum
   - Epidermophyton
   - Trichophyton
2. Dermatophyoses: Yeasts
   - Candida spp.

Question 11

Etiological agents that cause cutaneous mycoses are normally called ___

Answer 11

dermatophytes

Question 12

Cutaneous mycoses grown on hair, skin and nails and can utilize ___, but are inhibited by ___

Answer 12

keratin; blood

Question 13

True or False: Cutaneous mycoses are transmitted directly and are associated with tissue invasion, as well as mild inflammation

Answer 13

False - associated with no tissue invasion + mild inflammation

Question 14

What are dermpatophytes (cutaneous mycoses) preferred host?

Answer 14

1) Man
2) Lower animals
3) Soil with hair, skin, feathers

Question 15

Trichophyton infects __, __, and ___

Epidermophyton only infects ___ and ___

Microsporum infects __ and ___

Answer 15

hair, skin, and nails

skin and nails

hair and skin

Question 16

True or False: Tinea ___ is an example of a cutaneous mycoses

Answer 16

True

Question 17

Dermatophytes with a red ring lesion, that is scaly, grows outwards, is often called ___

Answer 17

ringworm

Question 18

True or False: 10% KOH wet mount preparation can be used to dx cutaneous mycoses

Answer 18

True

Question 19

How can you examine microscopic morphology of microconidia and
macroconidia (aka: cutaneous mycoses)?

Answer 19

Lactopheno cotton blue staining

Question 20

Which type of mycoses
result from traumatic implantation (via: skin penetration ) of fungi through the skin, which produces local lesions?
A. Cutaneous
B. Deep
C. Muscular
D. Subcutaneous

Answer 20

D. Subcutaneous

Question 21

Sporothrinx, a ___ fungus
can cause a subcutaneous mycosis condition known as _____

Answer 21

Dimorphic; Sporotichosis

Question 22

True or False: Sporothrix is found in gardens and is typically transmitted via traumatic implantation of fungus into the skin (e.g “rose gardener’s disease)

Answer 22

True

Question 23

____ is a condition characterized by nodular lesions, which often follow the lymphatic pathway, and are associated with chronic infection. Is it NOT contagious!

Answer 23

Sporotichosis

Question 24

Name the three systemic/endemic dimorphic fungi (true pathogens)

• Pathogens can produce disease in healthy host, initiated by inhalation of spores

Answer 24

1. Coccidioides
2. Histoplasma
3. Blastomyces

Question 25

True or False: Histoplasma capsulatum, Coccidioides immitis, Blastomyces dermatitidis are both endemic and dimorphic fungi

Answer 25

True

Question 26

The endemic mycoses is associated with ____

Answer 26

soil bird/bat dropping wood rotting

Question 27

Which condition would one likely see if one infected by one of these endemic fungi?

Answer 27

Asymptomatic 1 pulm infection

Question 28

Match the following A. Coccidioides B. Histoplasma C. Blastomyces

Answer 28

Question 29

_____: conidia that develop within the hyphae; asexual spore in the environment/culture)

Answer 29

Arthroconidia

Question 30

Coccidioides immitis in the Lung is seen as a spherule containing many ____

Answer 30

endospores

Question 31

C. immitis causes ___ ___

Answer 31

Valley fever

Question 32

In coccidiomycosis, spherules divide internally until they are filled with ___

Answer 32

endospore

Question 33

Blastomyces dermatitis (blastomycosis) causes ___ ____

Answer 33

cave disease

Question 34

Large, broad-base, unipolar budding yeast suggests ____, which is a blastomyces dermatitis Narrow-based buds of budding yeast suggests ____

Answer 34

blastomycosis H.capsulatum (histoplasmosis)

Question 35

What are four opportunistic fungi?

Answer 35

Question 36

True or False: C. albicans is found on Normal flora of skin, oral cavity, urogenital tract + most infections occur as a result of endogenous strains

Answer 36

True

Question 37

Thrush, vaginitis are caused by _____

Answer 37

C. albicans

Question 38

How can you dx C. albicans?

Answer 38

Germ tube test positive

Question 39

What is the main virulence used by Cryptococcus neoformans?

Answer 39

Encapsulated yeast

Question 40

True or False: Another common form of cryptococcosis is central nervous system infection, such as: meningoencephalitis. Skin lesions may also occur

Answer 40

True

Question 41

If an IC patient is infected with Cryptococcus neoformans, it could lead to serious infection -- particularly in the ___ ____

Answer 41

nervous system

Question 42

Which opportunisitic fungi requires india ink staining to see capsule directly from spinal fluid?

Answer 42

Cryptococcus

Question 43

Aspergillus is a mold that can be transmitted via: inhalation or ____, which causes cutaneous aspergillosis

Answer 43

Direct contact with break in the skin (surgery/burn wound)

Question 44

______: cavities in the lungs and fungal balls (aspergillomas) may also be present in the lungs

Answer 44

Chronic pulmonary aspergillosis

Question 45

True or False: Invasive aspergillosis affects the lungs, but it can also spread to other parts of the body (sinus, cerebral, or cutaneous sites) Cutaneous (skin) aspergillosis: direct or dissemination from lung.

Answer 45

True

Question 46

Which opportunistic fungi is a protozoan like fungi (yeast-like fungus) that can cause pneumocystis jirovecii pneumonia (PCP) -- which is pulmonary?

Answer 46

Pneumocystis jirovecii