Fungi Flashcards
(82 cards)
1
Q
Candida Albicans
A
Germ tube positive
2
Q
Candida spp.
A
Budding yeast, pseudohyphae, hyphae reverse dimorphism (nature: yeast, tissues: filamentous/yeast)
3
Q
Aspergillus
A
infectious pneumonia
Septated, dichotomously branching hyphae
4
Q
Zygomycetes
A
Non-septated
Medical emergency
produce Sporangiospores (asexual spore)
5
Q
encapsulated fungi
A
Cryptococcus neoformans
6
Q
Polymorphisms in what 3 PRR increase risk of which fungal infections
A
TLR4: candidiasis, asperguillus
MBL2: Candidiasis
DECTIN-1: candidiasis
7
Q
Budding yeast
A
Histoplasmosis
Cryptococcosis
Blastomycosis
Sporotrichosis
8
Q
Hyphae Fungi
A
Asperguillus, Dermatophytosis, Zygomycosis
9
Q
Both yeast and Hyphae
A
Candidasis and Tinea Versicolor
10
Q
Spherule
A
Coccidioidomycosis
11
Q
PAS Test
A
Periodic Acid-Schiff
stains polysaccharide cell wall
12
Q
GMS Test
A
Gomorri’s Methenamine Silver
Stains cell wall silver
13
Q
Fontana Masson Test
A
Stains melanin in cell wall of some fungi
14
Q
Mucicarmine or Alcian Blue
A
Stain capsule of Cryptococcus neoformans
15
Q
Superficial Fungal infection
A
Tinea Versicolor
16
Q
Mucocutaneous fungal infection
A
Dermatophytosis and mucocutaneous candidiasis
17
Q
Subcutaneous Fungal Infections
A
Chromoblastomycosis
Mycetoma
Sporotrichosis
18
Q
lymphocutaneous distribution
A
Sporotrichosis
19
Q
3 Dermatophytes that cause cutaneous fungal infections
A
Trichophyton spp
Microsporum spp
Epidermophyton Floccosum
20
Q
Ectothrix Invasion
A
arthroconidia form outside the hair shaft, cuticle is destroyed
Microsporum canis
Microsporum gypseum
Trichotyphoton equinumi
21
Q
Endothrix invasion
A
Arthroconidia form inside the hair shaft, cuticle is intact
Trichophyton tonsurans
Trichophyton violaceum
could be irreversible alopecia
22
Q
Which tinea can Trichophyton be?
A
Any Tinea
23
Q
Which Tinea can Microsporum be?
A
any tinea EXCEPT tinea unguium (nails)
24
Q
Which tinea is most common with Epidermophyton floccosum?
A
Tinea cruris (groin)
25
What is the most common cause of Tinea Pedis in the US?
| What is the most common cause of Tinea pedis worldwide?
1. Trichophyton rubrum
2 Microsporum canis
26
What immune response cause Dermatophyte inflammation
Cell-mediated immune response (lymphocytes)
| NOT neutrophils
27
What is used for laboratory diagnosis of superficial and cutaneous fungi?
KOH- used to dissolve Keratin
Calcofluor preparation- stains chitin in cell wall of fungi with fluorescent dye
Culture
Biopsy
28
What is the most common cause of Tinea capitis
Trichophyton Tonsurans
29
Treatment options for Tinea pedis, manuum, corporis, cruris?
Topical: clotrimazole, miconazole, ketoconazole, terbinifine
oral treatment if more extensive, severe, recalcitrant
30
Treatment options for Tinea capitis?
Oral antifungals:
| Topical to reduce spreading- Ketoconazole shampoo or Selenium sulfide shampoo
31
3 forms of Onychomycosis
Proximal Subungual Oncy. (PSO)- occurs in immunocompromised hosts and early indicator of HIV infection. infection of cuticle and spreads distally
DSO- most common type, often caused by T. rubrum, infection distally and spread proximally
WSO (White superficial): rare, fungus attacks dorsal surface of nail plate, minimal inflammation
32
Treatment for Onychomycosis?
Oral therapy: Griseofulvin, terbinafine, itraconazole,
33
What is Tinea Versicolor?
what is the yeast that causes it?
what does it look like histologically?
Treatment?
superficial mycotic infection of upper chest, neck, arms
caused by Malassezia furfur
Spaghetti and meatball appearance= hyphae, budding yeast
Topical treatment
34
What are the 3 opportunistic infections associated with decrease T cell function?
Mucocutaneous Candidiasis
Cryptococcosis
Pneumocystosis
35
What are the 3 opportunistic infections associated with neutropenia (altered phagocytic activity)?
Invasive Candidiasis
Asperguillosis
Zygomycosis
36
Risk factors for Mucocutaneous Candidiasis
```
Altered cell mediated immunity (T cell function)
HIV/Diabetes
pregnancy
age
steroids
antibacterial antibiotics
```
37
Features of Mucosal Candida?
| Features of Cutaneous Candida?
Mucosal: white pseudomembranous plaque
Cutaneous: erythematous, scalded lesion with satellite lesions, usually intertriginous (area where 2 skin surfaces rub)
38
Key histological features of Candida?
Hyphae, Pseudo-hyphae, budding yeast
39
Chronic Mucocutaneous Candidiasis
Inherited disorder of T cell immunity to Candida
autosomal recessive
Autoimmune Polyendocrinopathy candidosis ectodermal dystrophy (APECED)
40
Mucocutaneous Candidiasis treatment
Topical: Clotrimazole, Miconazole, Nystatin
Oral: Fluconazole
IV: Echinocardin (more severe cases)
41
Risk factors for Invasive Candidiasis
```
Altered barriers- vascular, urinary catheters, burns, trauma
neutropenia
transplant patients (BMT
hemodialysis
surgical patients
```
42
Which 2 fungi are angioinvasive?
Asperguillus
| Zygomycetes
43
Treatment of Invasive Candidiasis (Candidemia)?
IV Echinocardins- ideal
OR
IV AmpB or oral Fluconazole
44
Risk factors for Invasive Asperguillus (Pulmonary)
Neutrophil defect: neutropenia or altered neutrophil function
Chronic granulomatous disease (CDG)
BMT
high dose steroids
45
Asperguillus Pathology
Angular Dichotomous branching (acute angles) setptated hyphae
angioinvasion- hyphal invasion of lung parenchema and blood vessels, occlusion of blood vessels with necrosis of tissue
46
Asperguillus Radiological Evaluations of lungs
Halo Signs: zone of infarction surrounded by a zone of ischemia
Crescent sign- infection being cleared up by macrophages
47
Invasive Asperguillus Treatment
Voriconazole - treatment of choice
If pt has hepatic injury, use Amphoteracin B
48
What is the most common Zygomycosis?
Rhizopus
49
What is the most common form of zygomycosis disease? In which patient population is it often seen in?
Rhinocerebral zygomycosis
Diabetes mellitus with ketoacidosis
50
What is the 2nd most common form of zygomycosis infection? In which patient population is it seen in most?
Pulmonary Zygomycosis
Neutropenic patients
51
Pathology of Zygomycosis?
Wide Hyphae, nonseptated, infrequently branched at right angles
invasion of blood vessel walls and nerves
52
What fungus has sporangiophores?
Zygomycetes
53
Treatment of Invasive Zygomycosis?
Amphoterecin B
54
Description of Cryptococcosis?
opportunistic infection
caused by Cryptococcus neoformans
encapsulated yeast
often causing meningioencephalitis
55
What are the 3 common clinical diseases associated with Cryptococcus neoformans?
Pulmonary
CNS- meningioencephalitis
Disseminated
56
Who are most suseptible to getting a cryptococcosis infection?
T Cell compromised patients
| high dose steroids, immunosuppressants, HIV
57
Treatment of CNS Cryptococcosis?
Amphoteracin B and 5-FC (initial therapy)
| Fluconazole (maintenance)
58
What is Pneumocystosis?
| What are the symptoms?
an opportunistic pneumonia caused by pneumocystis carinii
diffuse alveolar infiltrate
fever, dyspnea, non-productive cough
59
Treatment of Pneumocystosis?
Trimethoprim-sulfamethoxazole
60
What are the 4 fungi that are pathogenic?
Histoplasma Capsulatum
Cocidioides immitis
Blastomyces dermatitidis
Paracoccidioides brasiliensis
61
What group of people are at increased risk of histoplasmosis?
T-cell compromised patients
| neutrophils play no role against Histoplasma
62
Histoplasma mimics which other disease?
TB
Xray looks the same as TB
will have multinucleate giant cells in a granuloma
63
What does pathology look like for Histoplasma?
chronic inflammation, granuloma with giants cells
| Caseous necrosis
64
Pathogenesis of Hisoplasmosis?
inhalation of asexual spores
phagocytosis by alveolar macrophages, but not killed
replication in phagolyosome
Intracellular budding yeast cells** (only fungi with intracellular yeast)
either formation of granuloma or dissemination to visceral organs depending on host immune response
65
What is the only intracellular budding yeast?
Histoplasma
66
Treatment of histoplasmosis
Itraconazole (mild to moderate)
| AmB for severe disease
67
What special polysaccharide is in the capsule of C. neoformans?
Glucuronoxylomannan
68
What are examples of ascomycetes?
Dermatophytes
| Histoplasma capsulatum
69
What are examples of basidiomycetes?
Cryptococcus neoformans
70
What is an example of deuteromycetes?
Many candida spp.
71
What is a common early indicator of HIV infection or other immune impairment?
PSO- proximal subungual onychomycosis
72
Treatment of Tinea Versicolor infection?
Ketoconazole or selenium sulfide shampoo to wash skin
Single dose of itraconazole or terbinifine
73
What is the most common anthropophic species of dermatophytes?
T. Tonsurans
74
What is an indication that a patient has candidemia rather than bacteremia?
Fever that is unresponsive to antibacterial antibiotics
75
Where is Histoplasma Capsulatum found?
soil and caves enriched with bat and bird feces
Ohio Mississippi River Valley
some parts of Maryland
76
Where is Coccidiodies Immitis Found?
Dessert soil of SW USA
| Sonoran valley climates of Latin America
77
Where is Blastocymces dermatitidis found?
in associated with water in north central and SE USA
78
Where is Paracoccidioides brasiliensis found?
South America,especially Brazil and Columbia
79
What are the characteristic structures of Coccidioides immitis?
Arthrocondia- in the environment, hyphal form, transmissible/infectious/what we inhale
Spherules- in tissues, contain endospores, not infectious
80
Majocchi's Granuloma
Variant of Tinea Corporis
follicles are disrupted and the fungus gets deeper in the dermis
common type: T. rubrum
81
What is the most common cause of Sporotrichosis?
Sporothrix schenkii
82
Classical history of rose gardening?
Sporothrichosis
