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