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96 Cards in this Set
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SAB agar
Mycosel |
SAB = Sabourad's agar. basic fungal plate
Mycosel is for DERMATOPHYTES (SAB + chloramphenicol + cyclohexamide) |
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What is cyclohexamide used for on Mycosel?
What important organisms can be missed due to the presence of cyclohexamide? |
Suppresses the saprophytic molds so the more slow-growing ones can grow
BUT ALSO SUPPRESSES: CRYPTOCOCCUS NEOFORMANS Trichosporon beigelii Candida tropicalis Yeast of Blastomyces Yeast of Histoplasma |
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Lactophenol cotton blue is usually used to stain?
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molds
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variant of histoplasma that is found in Africa and has more cutaneous and bony manifestations?
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H. duboisii
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What bands do we look for in an immune diffusion test for histoplasma?
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H & M bands!!
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Histoplasma capsulatum
Mold phase grown at 30C "tuberculate macroconidia" Large, 8-16uM |
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Histoplasma
Intracellular yeast 2-4uM |
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Leishmania
NOT histoplasma! Has kinetoplast |
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Visited Africa
Tuberculate macroconidia Yeast 8-10 uM |
histoplasma duboisii
Same mold form Yeast are 2x larger |
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Temperature for mold form
Temperature for yeast form |
Mold: Cold: <30C
Yeast: Heat: >35C |
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Look-alike fungus for Histoplasma?
Blastomyces? Coccidioides? |
Histo: Sepedonium (same macroconidia but not dimorphic and no microconidia)
Blasto: Chrysosporium (not dimorphic & grows at 3d) Coccidio: Malbranchea |
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blastomyces
lollipop conidia |
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Chrysosporium
(grows faster than blasto & is not dimorphic) |
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Broad based budding of blastomyces
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geographic area of coccidioides
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"sonoran life zone"
cooler areas of the desert, spread by inhaled dust SW US & mexico |
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Higher incidence of disseminated cocci in what populations?
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HIV, darker skinned ethnic groups, and pregnancy
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Coccidioides immitis
septate hyphae are thick walled, barrel shaped, with dead cells in between |
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What dimorphic fungus grows solely as a mold in the lab, but has a yeast form in the body?
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Coccidioides
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Coccidioides
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Rhinosporidium, mucin stain. has spherules like coccidio BUT is much larger (100-300uM vs 10-80!)
Nasal and oral, not lung and deep tissue |
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Paracoccidioides brasilensis
YEAST FORM! (histo can look like this but in the MOLD form at 30C) |
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Nocardia vs. actinomyces
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Both are gram +, filamentous branching bacteria
Nocardia is partially acid fast actinomyces is an anaerobe |
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What is the difference between partial acid fast stain and a true acid fast stain?
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Partial: Uses H2SO4 as a decolorizer
True: Uses HCl as a decolorizer |
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What is the name for the clinical syndrome of:
1. Swollen lesions on extremities 2. Draining sinuses 3. Sulfur granules |
Mycetoma
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What are the types of mycetoma?
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1. Actinomycotic (98%!) bacterial! not fungal. Nocardia, streptomyces, actino
2. Eumycotic |
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Sulfur granule with actinomyces
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Sulfur granule of mycetoma with nocardia
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Molar tooth colony of actinomyces
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How to differentiate the dimorphic fungi based on growth characteristics?
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All grow as a white fluffy mold
Coccidio will grow FAST - in 2-3days Histo & blasto take weeks |
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SAB agar, 3-5 days, musty odor
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Nocardia
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Nocardia. gram +, can look like gpc in chains
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Brown mold
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Curvularia
Cause of eumycotic mycetoma |
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Mycetoma
1. Swollen lesions on extremities 2. Draining sinus 3. Sulfur granules 98% caused by actinomyces group, 2% dematiaceous fungi |
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Chromoblastomycosis
1. wart like lesions 2. SCLEROTIC BODIES in tissue 3. Dematiaceous fungi |
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Sclerotic body of chromoblastomycosis
"copper penny" |
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One of the three main types of sporulation of dematiaceous fungi that cause chromoblastomycosis. Has conidias going along the conidiophore
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Rhinocladiella-like sporulation
Dematiaceous fungus (can tell by brown hyphae) |
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One of the three main types of sporulation of dematiaceous fungi that cause chromoblastomycosis. Looks like a flower.
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Phialospora-like sporulation
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One of the three main types of sporulation of dematiaceous fungi that cause chromoblastomycosis.
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Cladosporium-like
Branching chains of conidia This one can go to brain! |
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Diagnostic structure in:
Mycetoma? Chromoblastomycosis? |
Sulfur granules
Sclerotic bodies |
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Sclerotic body of chromoblastomycosis in tissue section
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Lymphocutaneous spread up the arm
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Sporotrichosis
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Dimorphic dematiaceous fungus, growth 3-5d
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Sporothrix schenckii
mold at 30C, yeast at 37C |
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30degree culture from rose thorn prick
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Sporothrix schenckii
Mold form delicate septate hyphae with daisy head arrangement of spores |
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37C culture from rose thorn
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Sporothrix
Long oval yeast = "Cigar bodies" the only long oval yeast in mycology |
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What is the best way to diagnose sporothrix?
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CULTURE!
you will NEVER see the yeast form in tissue! You can see something else though... see next question |
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2 names for this phenomenon, that has a variety of infectious and non-infectious causes
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Asteroid body
Splendore-Hoeppli phenomenon in vivo formation of intensely eosinophilic material (radiate, star-like, asteroid or club-shaped configurations) around microorganisms (fungi, bacteria and parasites) or biologically inert substances. |
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What fungal organism is classically related to catheter-related infectious in kids?
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Candida parapsilosis
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What 3 canidida types can be resistant to fluconazole?
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C. glabrata
C. kruseii C. tropicalis |
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Name two tiny yeasts (4 uM)
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Histoplasma (intracellular)
Candida glabrata (extracellular) |
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What is different about Candida (torulopsis) glabrata?
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1. Tiny. (4uM) compared to other candidas (7uM)
2. does NOT form pseudohyphae 3. Is one of the types that can be resistant to fluconazole |
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What are the 2 types of candida that are germ tube test positive? How to tell apart?
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C. albicans (sucrose -)
C. stellatoidea (sucrose +) **Must read at 4 hours - many fungi will give false positives at longer incubations** |
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C. albicans ID in the lab (2 things)
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1. Germ tube test +
2. Makes chlamydospores on cornmeal agar |
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Test?
How long does it take? |
Chlamydospore of candida albicans
48 hours at 30C on cornmeal agar; this is the resting state |
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Candida
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Neonatal receiving lipid TPN. fungemia with?
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Malassezia furfur
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Malassezia furfur
Budding yeast 2-4uM with COLLARETTE around the neck |
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spaghetti & meatballs of malassezia furfur
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Point of care test for dermatophyte?
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KOH prep. not ideal.
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Microsporum canis
(dog/cat ringworm) (dermatophyte) |
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Microsporum gypseum
beige & soil-like (dermatophyte) Macroconidia don't have as thick walls or dividers as M. canis |
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Reverse side of plate is red
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Trichophyton rubrum
(dermatophyte) |
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Trichophyton rubrum
Pencil shaped macroconidia MANY microconidia |
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#1 cause of epidemic tinea capitis in kids
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Trichophyton tonsurans
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Epidermophyton floccosum
Beaver-tail spores No microconidia characteristic microscopic (dermatophyte) |
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India ink
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Cryptococcus neoformans
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Only yeast that is inositol positive?
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Cryptococcus.
Also urease+!! (positive is PINK) |
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Vector of cryptococcus?
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Pigeon poop
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Birdseed agar.. what organism turns chocolate brown?
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Cryptococcus neoformans
mucoid turns brown with time (BIRDSEED AGAR!!) |
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what stain is this?
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Mucicarmine. cryptococcus
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Aspergillus fumigatus
blue-green mold |
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Aspergillus fumigatus
(paintbrush, broom) |
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Aspergillus flavus
Yellowish mold |
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Aspegillus flavus
"sunburst" |
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Aspergillus niger
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Aspergillus niger
black spores, all around |
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Aspergillus in tissue
septate hyaline hyphae with 45 degree branching |
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Patient with keratitis or bone marrow transplant
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Fusarium
BANANAS |
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Fusarium
FUSCHIA |
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Penicillium
can look a lot like aspergillus! no swollen vesicle... the spores come straight out |
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This type of penicillium is always pathogenic, and mimics T rubrum.
classically: Skin infections in SE Asia Pulmonary infections in AIDS patients |
P marneffei
- greenish colony with RED DIFFUSIBLE PIGMENT! (vs T rubrum - white colony with red diffusible pigment) board favorite! |
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The only penicillium that is dimorphic?
(yeast in tissue, hyphae in lab 30C) |
P. marneffei
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Examples of hyaline molds
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Aspergillus
Fusarium Penicillium |
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Examples of demateaceous molds and their classic diseases:
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Demateaceous molds:
Alternaria, bipolaris, curvularia, exophiala Characterized by the disease caused: -Eumycotic mycetoma (swollen lesions on extremities, draining sinuses, sulfur granules) -Chromoblastomycosis (wart-like lesions, sclerotic bodies in tissue) -Phaeohyphomycosis (subcutaneous soft tissue lesions) |
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Examples of phaeohyphomycosis:
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Alternaria
Bipolaris Curvularia pseudallereschia |
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Bathroom wall
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Alternaria
"Hand grenades" chaining |
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Very invasive
Requires multiple debridements |
Bipolaris
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Curvularia
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This demateaceous fungus can mimic aspergillus in tissue and in diseases caused (vasoinvasion).
what else can it mimic? |
Pseudallescheria boydii
Must do culture! (it can also mimic blasto - lollipop conidia - but the lab can easily tell apart as blasto is not brown, and takes 2-3 weeks to grow...) |
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What is the asexual form of pseudallereschia called?
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Scedosporium
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"Lid lifters"
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Zygomycetes
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What special things should we do in the lab when we suspect a zygomycete?
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Mince & put a piece of tissue in agar
do NOT grind! zygomycetes have long hollow hyphae that can be destroyed, vs a hyaline mold which has septae and separate cells which can survive grinding |
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Rhizopus, a zygomycete
roots directly under sac |
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Absidia, a zygomycete
roots not directly under sac |
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Rhinocerebral disease in a diabetic
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Mucor, a zygomycete
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Zygomycetes
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Rhizopus (rhizoid/roots under sac)
Absidia (rhizoides elsewhere) Mucor (no rhizoids) long hollow tube |
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90 degree branching
aseptate |
Zygomycosis
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