L22: Introduction to Human Fungal Infections Flashcards
Most fungal pathogens are NOT communicable, except….
Dermatophytes
True or False: Fungi are mostly opportunistic
True
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.
True
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
Superficial ; B.) M. furfur
True or False: Tinea versicolor is lipophobic and contagious
False - it is lipoPHILIC and NOT contagious
True or False: Tinea versicolor arises due to overgrowth of normal flora
True
How can you diagnose T. versicolor using Wood’s Lamp?
Hyper-pigmentation
- Lesions will fluoresce
- YELLOW
Hypo-pigmentation
Which of the following skin conditions reveals yeast that has a “spaghetti and meatballs” appearance?
Tinea Versicolor
What are the two big groups of Cutaneous Mycoses known as?
- Dermatophyoses: Molds
- Microsporum
- Epidermophyton
- Trichophyton - Dermatophyoses: Yeasts
- Candida spp.
Etiological agents that cause cutaneous mycoses are normally called ___
dermatophytes
Cutaneous mycoses grown on hair, skin and nails and can utilize ___, but are inhibited by ___
keratin; blood
True or False: Cutaneous mycoses are transmitted directly and are associated with tissue invasion, as well as mild inflammation
False - associated with no tissue invasion + mild inflammation
What are dermpatophytes (cutaneous mycoses) preferred host?
1) Man
2) Lower animals
3) Soil with hair, skin, feathers
Trichophyton infects __, __, and ___
Epidermophyton only infects ___ and ___
Microsporum infects __ and ___
hair, skin, and nails
skin and nails
hair and skin
True or False: Tinea ___ is an example of a cutaneous mycoses
True
Dermatophytes with a red ring lesion, that is scaly, grows outwards, is often called ___
ringworm
True or False: 10% KOH wet mount preparation can be used to dx cutaneous mycoses
True
How can you examine microscopic morphology of microconidia and
macroconidia (aka: cutaneous mycoses)?
Lactopheno cotton blue staining
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
D. Subcutaneous
Sporothrinx, a ___ fungus
can cause a subcutaneous mycosis condition known as _____
Dimorphic; Sporotichosis
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)
True
____ is a condition characterized by nodular lesions, which often follow the lymphatic pathway, and are associated with chronic infection. Is it NOT contagious!
Sporotichosis
Name the three systemic/endemic dimorphic fungi (true pathogens)
- Pathogens can produce disease in healthy host, initiated by inhalation of spores
- Coccidioides
- Histoplasma
- Blastomyces
True or False: Histoplasma capsulatum, Coccidioides immitis, Blastomyces dermatitidis are both endemic and dimorphic fungi
True
The endemic mycoses is associated with ____
soil
bird/bat dropping
wood rotting
Which condition would one likely see if one infected by one of these endemic fungi?
Asymptomatic 1 pulm infection
Match the following
A. Coccidioides
B. Histoplasma
C. Blastomyces
_____: conidia that develop
within the hyphae; asexual spore
in the environment/culture)
Arthroconidia
Coccidioides immitis in the Lung is seen as a spherule containing many ____
endospores
C. immitis causes ___ ___
Valley fever
In coccidiomycosis, spherules divide internally until they are filled with ___
endospore
Blastomyces dermatitis (blastomycosis) causes ___ ____
cave disease
Large, broad-base,
unipolar budding yeast suggests ____, which is a blastomyces dermatitis
Narrow-based buds of budding yeast suggests ____
blastomycosis
H.capsulatum (histoplasmosis)
What are four opportunistic fungi?
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
True
Thrush, vaginitis are caused by _____
C. albicans
How can you dx C. albicans?
Germ tube test
positive
What is the main virulence used by Cryptococcus neoformans?
Encapsulated yeast
True or False: Another common form of cryptococcosis is central nervous system infection, such as: meningoencephalitis. Skin lesions may also occur
True
If an IC patient is infected with Cryptococcus neoformans, it could lead to serious infection – particularly in the ___ ____
nervous system
Which opportunisitic fungi requires india ink staining to see capsule directly from spinal fluid?
Cryptococcus
Aspergillus is a mold that can be transmitted via: inhalation or ____, which causes cutaneous aspergillosis
Direct contact with break in the skin (surgery/burn wound)
______: cavities in the
lungs and fungal balls (aspergillomas) may also be
present in the lungs
Chronic pulmonary aspergillosis
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.
True
Which opportunistic fungi
is a protozoan like fungi (yeast-like fungus) that can cause pneumocystis jirovecii pneumonia (PCP) – which is pulmonary?
Pneumocystis jirovecii
