Mycology Flashcards
1
Q
Culture medium of fungi
A
Saboraud’s agar
2
Q
Low pH 5.6 inhibits growth of bacteria but permits growth of filamentous fungi and yeast
Impregnated with chloramphenicol and gentamicin to inhibit growth of other bacteria
A
Saboraud’s agar
3
Q
Used to dissolve tissue material leaving the alkali resistant fungi intact
A
10% KOH
4
Q
Fungal wall constituent
A
Chitin
Ergosterol
Beta glucan
Mannoproteins
5
Q
Protein found in exoskeleton and wall of fungi
A
Chitin
6
Q
Sterol of the cell membrane of fungi and cell wall of protozoans regulates permeability and fluidity of fungal cell wall
A
Ergosterol
7
Q
Most abundant polysaccharides of the fungal wall
A
Betaglucans
8
Q
Opportunisitc mycosis
A
Candidiasis
Cryptococcus neoformans
Histoplasma
Pneumocystis carinii
9
Q
Fungi that infect only the keratinized tissue (skin, hair and nails)
A
Cutaneous mycosis
10
Q
Cutaneous mycosis
A
Microsporum
Trichophyton
Epidermophyton
11
Q
Affects skin, hair and nails
A
Trichophyton three
12
Q
Affects only skin and hair
A
Microscporum
13
Q
Affects only skin and nails
A
Epidermophyton
14
Q
Ringworm of scalp
A
Tinea capitis
15
Q
Ringworm of bearded region
A
Tinea barbae
16
Q
Ring worm of glabrous skin
A
Tinea corporis
17
Q
Jock itch
A
Tinea cruris
18
Q
Athlete’s foot
A
Tinea pedis
19
Q
Most serious of tinea capitis
A
Tinea favosa/favus
20
Q
Most common cause of outbreaks of tinea capitis in children
Main cause of endothrix
A
Trichophyton tonsurans
21
Q
Dermatophyte infections that invade hair shaft and internalize into hair cell
A
Endothrix
22
Q
Dermatophyte infectikn confined to the hair surface
A
Ectothrix
23
Q
Severe tinea capitis
A
Tinea favosa
Trichophyton schoenleinii
24
Q
Causes tinea favus
Tinea capitis presenting with crust on the scalp
Most serious form causing permanent scarring and scalp hair loss
A
Trichophyton schoenleinii
Tinea favus
25
Zoophilic tinea capitis
Microsporum canis
| Trichophyton mentagrophytes
26
Young child showing a large circular erythematous scaly lesion with a raiser border on the nose
Microsporum gypseum
27
Tinea barbae
Trichophyton verrucosum
Trichophyton mentagrophytes
Trichophyton rubrum
28
Most prevalent systemic mycosis
Candidiasis
| Candida albicans
29
Appear as yeast or pseudohyphae
Germ tube formation in serum at 37 deg
Candida albicans
30
Grow as oval, budding yeast cell (3-6 um in size)
Also form pseudohyphae when buds continue to grow
Candida albicans
31
On agar media or within 24h at 37 deg or room temperature
Soft, cream-colored colonies with a yeasty odor
Candida albicans
32
Can infect kidneys
Attach to prosthetic heart valves or produce candidal infections almost anywhere (eg arthritis, meningitis, endopthalmitis)
Oral candidiasis
Vaginal
Candida
33
Cottage cheese discharge
| DM
Vaginal candidiasis
34
Esophageal candidiasis risk factor
Radiation
| Chemotherapy
35
Candida tx
Nystatin
36
Thrush and mucocutaneous form of candidiasis Tx
Topical Nystatin
| Oral Ketoconazole or Fluconazole
37
Systemic candidiasis tx
Amphotericin +/- oral flucytosine
38
AIDS
Pigeon
Yeast from CSF stained with india ink
Meningitis
Cryptococcus neoformans
39
Bird or bat dropping
Histoplasma
40
Pigeon dropping
Eucalyptus tree
Encapsulated yeast cell (India ink)
Meningitis
Cryptococcus neoformans
41
Cryptococcus neoformans Dx
India ink
| Cryptococcal antigen latex agglutination (CALAS)
42
HIV defining illness (CD <200)
| CD <100 this infection sets in
Cryptococcus neoformans
43
Severe interstitial pneumonia in immunocompromised patients especially AIDS patients
Previously protozoan -> 1988 yeast
Pneumocystis carinii
| Pneumocystis jiroveci
44
P jiroveci Dx
Gomori methenamine Silver stain of lung tissue broncheoalveolar lavage
Transbronchial lung biopsy
45
P jirovecii Tx
Trimethoprim-sulfamethoxazole
| Pentamidine (aerosol)
46
P jiroveci Hallmark of xray
Severe hypoxemia
Ground glass opacities
Pneumonia
47
TMP SMZ SE
| No 1 cause
SJS
48
Transmitted by droplet inhalation, close contact
Immunosupression
Pneumonitis spreading from hilar areas
Gomori’s mehanamine silver stain
Pneumocystis carinii
49
Common cause of death in HIV patients
Pneumocystis jiroveci
50
Hypopigmented spots on chest and back
Malasezzia furfur
| Pityriasis Tinea versicolor
51
Malasezzia furfur pathognomonic histology
Spaghetti and meatballs budding yeast cells and hyphae
52
Oval macules and patches with fine scaling
Light brown/pink in light skin; white in dark skin
Back, upper trunk, upper arms, axillae, thighs
Asymptomatic or mild pruritus
Malassezia furfur
53
Malassezia furfur Dx
KOH - spaghetti and meatballs (filamentous hyphae and budding yeast)
54
Malassezia pityriasis versicolor Tx
Selenium sulfide (selson blue) shampoo
Ketoconazole shampoo
Azole cream
Fluconazole and ketoconazole oral
55
Lice: difficult to find
Nits: oval, gray/white egg capsules (1mm), firmly cemented to the hair, recent infestation, nits are near the scalp, long standing infection
Pediculosis humanis capitis
56
Lays 5-6 nits a day
Eggs hatch and in 7-10 days become nymph
Later adult
Pediculosis
57
Pediculosis Dx
Microscopy of nits and lice
58
Pediculosis Tx
Permethrin lotion
| Ivermectin
59
Excoriated erythematous papules
Lice and nits on clothing seams
On the body
Pediculosis corporis
| Pediculosis humanus humanus
60
Sexually transmited
1-2mm brownish gray specks in hairy areas
Nits attached to hair shafts
Papular urticaria, maculae ceruleae (dlste colore macule)
Pediculosis pubis
| Pthirus pubis
61
Pthirus pubis Tx
1% Permethrin lotion
| Mousse containing pyrethrins and piperonyl butoxide
62
Scabies is caused by
Sarcoptes scabei
63
Caused by mites which cause extreme nocturnal itching (tunnels and lays eggs)
Scabies
64
Scabies site of predilection
```
Interdigital web
Wrist
Penile shaft
Genitals
Buttocks
Axillae
Abdomen
```
65
Appears as dark lines between fingers and toes, body flexures, nipples and genitalia
Excoriated papules, burrows, inflammatory nodules
Scabies
| Seven year itch
66
Scabies Tx
Permethrin 5% with corticosteroids
Washing of beddings and clothes is necessary
Topical corticosteroids may be necessary to treat itching
67
Unbranched sporangiophores that arise opposite rhizoids
Rhizopus
68
Hyaline to faintly pigmented
| Simple or sometimes branched arising solitary
Rhizopus
69
>90 degree branching mold
Mucormycosis
70
Ketoacidosis
Leukemia
Black nasal discharge
are encountered in
Mucormycosis
71
Dimorphic fungus (exists in yeast or mold form)
Rose gardener’s disease
Sporothrix schenckii
| Sporotrichosis
72
Sporothrix scheckii is seen in tissue soecinens as
Cigar shaped budding yeast
| Flowerette arrangement of conidia
73
Packs of cigar on examination
M leprae
74
Sporothrix form at temperature less than 37 degrees
Hyphal
75
Sporothrix form more than 37 deg
Budding yeast
76
Central fungus cell with eosinophilic material radiating from cell of Sporotrix
Asteroid body
77
Initial lesion develops as granulomatous nodule that may progress to form a necrotic or ulcerative lesion
Draining lymhpatics become thickened and cord-like
Botanist, flower shop
Cutaneous sporotrichosis
78
Acid fast stain for Cryptosporidium modified
Kinyoun stain
79
Most common symptom of Cryptosporidium
Watery diarrhea
80
```
Stomach cramps
Dehydration
Nausea
Vomiting
Fever
Weight loss
```
Cryptosporidium
Immunocompromised
HIV/AIDS
Cancer
Inherited deficiency
81
Cryptosporidium Tx
Nitazoxanide
82
Ixodes tick
| Maltese on blood smear
Babesia microti
83
Lyme disease
| Ixodes tick
Borellia burgdorferi
84
Two hosts in life cycle of babesia
Rodent (white footed mouse)
| Ixodes tick
85
```
Fever
Chills
Sweating
Myalgia
Fatigue
Hepatosplenomegaly
Hemolytic anemia
```
Babesiosis
86
Babesia Tx
Atovaquone + azithromycin
87
Typical brown diffusable pigment in agar
On the foot
Madurella mycetomatis
88
Caused by actinomycotic mycetoma or actinomycetoma
Madurella
Farmers, hunter gatherer, chronic granulomatous soft tissue infection
Madura foot
89
Madura foot Tx
Itraconazole
| Ketoconazole
90
Barrel shaped arthroconidia
Coccidioides immitis
91
Highest endemism in semiarid areas
San Joaquin Valley Fever
Coccidioides immitis
92
Mold in soil, spherule in tissue
| In soil it forms hyphae with arthrospores and empty cells
Coccidiodes immitis
93
Desert areas of Western US and Northern Mexico
Transmission: respiratory
Dimorphic fungus
Mycelia forms with spores at 25 deg celsius
Yeast forms at 37 deg Celsius
Coccidioides immitis
94
Coccidiodes immitis Tx
Fluconazole
| If it disseminate in CNS causing meningitis
95
Mariner pilot’s wheel
Thick walled yeast with multiple buds
Armadillo
Fruit bat
Coccidioides brasilienses
96
Coccidioides brasiliensis Dx
Direct sputum examination
BAL fluids
Scrapings from mucocutaneous ulcer
97
```
Oral lesions
Weight loss
Lymph adenopathy
Cough
Fever
SOB
```
Coccidioides brasiliensis
Diff dx
TB
HIV
98
Paracoccidioides Tx
Itraconazole
Amphotericin
With or without Trimethroprim-sulfamethoxazole
99
Dichotomously branching hyphae
Aspergillus fumigatus
100
Invasive pulmonary aspergillosis
Aspergillons
Otomycosis
Aspergillosis
101
Forms fungus balls in the lungs
| Seprate hyphae that form V shaped dichotomous branches
Aspergillus fumigatus
102
Most common form of fungal sinusitis
Aspergillus
103
Broad based budding yeast
Blastomyces dermatitidis
104
North American Blastomycosis
Chicago disease
Gilchrist disease
Systemic blastomycosis
105
Most common extrapulmonary manifestation of blastomycosis
Skin disease
106
Tuberculate macroconidia and micronidia
Soil contaminated with bird droppings
Oval yeast cells
Bird droppings in caves
Histoplasmosis capsulatum
107
Spelunker’s disease
Histoplasmosis
108
Mimics pulmonary TB in xray
| Cough, hemoptysis, DOB
Histoplasmosis
109
Fungi used in making bread, beer and wine
Saccharomyces cerevisiae
