Stoeckel- fungi Flashcards
this is a pretty half-assed deck compared to all the other subjects. sorry guys
Many pathogenic fungi exist as ______ and ______
molds (multicellular) and yeasts (unicellular
______ forms more typical at human body temperature
Yeast
although yeast forms are the predominant form of fungal pathogens, which species is the exception?
Candida – mold (mycelial) form found in tissue
what is the importance of pathogenic fungi in the big picture of human health?
opportunistic infections caused by commensal (Candida) or fully saprophytic (Aspergillus) species almost exclusively invade the immunocompromised hosts
fungi do not cause the same diseases- each species causes its own disease
what are primary mechanisms for containing fungal infections?
Neutrophil phagocytosis and killing
what are the primary barriers for fungi?
Intact skin and mucosal surfaces
what are Mycoses?
fungal infection of animals, including humans
what are endemic mycoses?
- Infections caused by fungal pathogens that are restricted geographically
- True pathogens that typically result in systemic infections in healthy individuals
what are opportunistic mycoses?
- Infections caused by fungi that are not true pathogens
- Cause systemic infections only in immunocompromised patients
Histoplasma capsulatum (histoplasmosis) is a _______ fungal pathogen
Endemic Fungal Pathogen
what can cause a fungi such as histoplasma to become disseminated (reach the whole body)?
Cell-mediated immune deficiencies such asT-cell function defects (e.g., AIDS, immunosuppressive therapy)
Normally, the human body can use _______________ to prevent the spread, and destroy, mycoses
cell-mediated immunity
Histoplasmosis is normally found where?
mid-southeastern U.S
indiana gets hit really hard
histoplasmosis is a _______________ system infection
Reticuloendothelial system infection
infects phagocytic cells- travels through the lymph system
Blastomycosis is primarily found where?
Found primarily in the Mississippi River Valley and southeastern states
-can also be found in canada
Coccidioidomycosis is found where?
-only in lower Sonoran life zone (dry areas)
Arizona, southern California, New Mexico, Texas
________ are highly infectious endemic mycoses; inhaled into alveoli
C. immitis
-species of Coccidioidomycosis
Desert rheumatism or Valley Fever is caused by which fungi?
C. immitis
what is a complication from Disseminated coccidiodiomycosis?
Chronic meningitis
which fungi is the most frequent opportunistic fungal pathogen ?
Candida albicans
__________ Do not cause infection unless normal flora is disrupted
Candidiasis
Candidiasis can follow _________ and central intravenous catheters
superficial infections
diseases caused by Candidiasis:
1) Thrush
2) Intertriginous candidiasis (diaper rash)
3) Disseminated infection- the serious one
which fungi is typically found in soil contaminated with bird droppings?
Cryptococcus (neoformans)
-Histoplasma capsulatum’s GROWTH is accelerated by droppings
T/F: Aspergillus is part of our normal flora
False- found in air, soil, water
______________ are the most common fungal infections in humans
Dermatophyte Skin Infections
athlete’s foot, ringworm, jock itch, jungle rot
name the 3 common dermatophyte Infections from “ringworm”
1) tinea capitis (scalp)
2) tinea corporis (body)
3) Tinea pedis (Feet)
Anthropophilic dermatophytes:
- Trichophyton
- Epidermophyton
zoophilic dermatophytes:
Microsporum canis
what factors are required for dermatophyte entry?
Skin trauma
Continuous moist conditions important
fungal infections are regularly seen in what population groups?
patients with untreated AIDS;
patients with cancer and undergoing chemotherapy;
patients with transplants on immunosuppressive agents;
some patients taking long-term corticosteroids
Polyenes affect the __________ of fungi
cell wall
-they create channels in the wall when they bind to ergosterol
Azoles will combat fungal infection by interfering with what?
ergosterol synthesis
______________ immunity is required to eliminate fungal infections
T cell-mediated immunity
how do Subcutaneous Mycoses enter the skin?
via thorns or splinters
why is Sporotrichosis called the “rose growers disease”
the fungi enter skin via thorns or splinters
Candida is in the ________ form when infecting
mycelial form
Caspofungin and micafungin are effective against which fungi? how are these drugs administered?
- Candida and Aspergillus species
- only given in IV
Candida and Aspergillus are both causes of disease in their ________ form
filamentous form
are hyphae not unicellular
“Tinea” is the name for any form of what mycoses?
superficial cutaneous mycoses
why is Tinea often confused with a parasitic (worm) infection?
due to the raised infection
its causes “ringworm”, but its a fungus
what are the conditions necessary for ringworm infections?
1) crowding of people
2) moist conditions
3) skin trauma
Subcutaneous Mycoses are also known as what?
- “Mycoses of implantation”
- enter skin via thorns or splinters
Mycetoma can cause chronic infections of the ______
sinuses
Allylamines will block _______ synthesis
ergosterol
Allylamines are effective against which fungi?
- dermatophytes
- C. albicans
(can be given as a pill or a cream)
instead of using sterols (cholesterol) like animal cells, fungi will use ________ in their cell membranes
ergosterol
almost all fungi are strict aerobes. what is the exception to this rule?
bakers yeast
after histoplasma is inhaled, it will evade _______ barriers and transform to its ______ phase
evade mucousal barriers
transform into yeast phase
histoplasmosis symptoms can be either __________ or __________
Pulmonary (lungs) or disseminated (seen on the skin)
what is the “hallmark” symptom of blastomycosis?
Skin lesions develop as a result of hematogenous dissemination
histoplasmosis and blastomycosis can both form __________, which can allow the fungi to remain viable for long periods
Granulomas
once inhaled, Coccidioides will transform to large __________that are filled with hundreds of endospores
spherules
Tinea versicolor causes what symptoms?
Hypopigmented or hyperpigmented patches on chest or neck with scaling
T/F: azeroles will kill fungi by interfering with ergosterol synthesis
False- they are fungistatic, meaning they stop fungi spread/division. they won’t kill a fungi cell that already has a developed cell wall
Mucormycosis (an opportunistic fungi) can cause which 2 clinical diseases?
1) Rhinocerebral form - unique to diabetics
2) Disseminated mucormycosis
- this is similar to the pulmonary lesions of aspergillosis
name the “pulmonary fungi” discussed in this lecture
1) Cryptococcus
2) Aspergillus
3) Mucormycosis
4) Pneumocystis
name the “superficial cutaneous fungi” discussed in this lecture
1) Malassezia
2) ringworm (cause tineas)
- Microsporum
- Trichophyton
- Epidermophyton
name the “subcutaneous fungi” discussed in this lecture
1) Sporothrix schenckii
- causes Sporotrichosis
2) Mycetoma
(Chromoblastomycosis caused by a few different species)
name the “endemic fungi” discussed in lecture
1) Histoplasma capsulatum
2) Blastomyces dermatitidis
3) Coccidioides immitis
list all of the “opportunistic fungi” discussed in this lecture
1) Candida
2) Cryptococcus
3) Aspergillus
4) Mucormycetes
5) Pneumocystis
the term “Anthropophilic” when referring to dermatophytes means what?
exclusively in humans and their habitat
these dermatophytes often cause chronic infections
both of the anthropophilic dermatophytes discussed have names that end in “phyton”…… name these 2 little bastards
Trichophyton
Epidermophyton
which dermatophyte genera is geophilic? (meaning its found in soil)
microsporum
Caspofungin and micafungin both belong to which class of antifungals?
(this class is the “new” antifungals)
Echinocandins
Echinocandins will inhibit the formation of what?
fungal cell wall
they are the “penicillin of the antifungals”
