MYCOVIRO - CH 60 of book part 4 Flashcards Preview

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Flashcards in MYCOVIRO - CH 60 of book part 4 Deck (33):
1

broad based yeast


Blastomyces dermatitidis

2

circular to pyriform (dumb-bell) conidia, lollipop conidiophores


Blastomyces dermatitidis

3

“prickly state” – tufts of hyphae projects upward


Blastomyces dermatitidis

4

Exoantigen test or nucleic acid probe testing: presence of A band


Blastomyces dermatitidis

5

direct exam of sputum or lung aspirate

Coccidioides immitis

6

observe non-budding thick-walled spherule


Coccidioides immitis

7

spherule either contains granular material or endospores

Coccidioides immitis

8

alternate arthroconidia – arthroconidia separated by disjunctor cells


Coccidioides immitis

9

small septate racquet hyphae; rectangular to barrel-shaped arthroconidia (stains with
lactophenol cotton or aniline blue)

Coccidioides immitis

10

wet preparation: sterile saline + petrolatum, incubated overnight

Coccidioides immitis

11

empty, collapsed “ghost” spherules may be present (bc of release of endospores)

Coccidioides immitis

12

delicate cobweb-like growth

Coccidioides immitis

13

Some have aerial hyphae, others have vegetative hyphae (adhere to agar surface)

Coccidioides immitis

14

fluffy white, greenish discoloration on blood agar

Coccidioides immitis

15

should be examined only under Level 3 BSC; culture should be sealed with tape to prevent
infection; screw-capped tubes must be used

Coccidioides immitis

16

Histoplasma capsulatum
- Stain and specimen ??

Wright- or Giemsa-stained bone marrow specimens

17

found intracellularly in mononuclear cells as small round yeast cells
o


Histoplasma capsulatum

18

small, intertwined hyphae
large, spherical or pyriform, smooth-walled macroconidia (characteristic tuberculate with age)
echinulate macroconidia (?)


Histoplasma capsulatum

19

to remove contamination in H. capsulatum:

uses yeast extract/ phosphate medium and a drop of conc NH4OH

20

recovered from blood culture within 8 days


Histoplasma capsulatum

21

white, fluffy mold that turns brown to buff with age
tufts of hyphae project upward


Histoplasma capsulatum

22

mariner’s wheel, mickey mouse cap

Paracoccidioides brasiliensis

23

heaped with crater formations, wrinkled, moist, yeastlike colonies o covered with short aerial mycelium and turns tan to brown with age

Paracoccidioides brasiliensis

24

test for definitive identification of Paracoccidioides brasiliensis

Exoantigen test:

25

no budding cells
extensively branched and highly septate hyphae
may be detected in peripheral blood smears in disseminated infection o mycelial forms produce brush-like conidiophores (penicillus)

Penicillium marneffei

26

observe small, yeastlike cells with septa; reveals annelid formation

Penicillium marneffei

27

produces blue-green to yellowish colonies on Sabouraud’s o soluble red to maroon pigment diffuses into agar

Penicillium marneffei

28

Stain: exudate aspirated from unopened subcutaneous nodules or from open draining lesions

Sporothrix schenckii

29

small, round to cigar-shaped yeast cells

Sporothrix schenckii

30

stained using periodic acid-Schiff (PAS) method

Sporothrix schenckii

31

amorphous pink material may be seen surrounding the yeast cells
delicate, septate, branching hyphae
single-celled conidia in clusters from tips of single conidiophores (rosette/flowerette
arrangement)

Sporothrix schenckii

32

initially at 37C: small, moist, white to cream colored colonies
becomes membranous, wrinkled, and coarsely matted, leathery, dark brown to black colonies

Sporothrix schenckii

33

useful for diagnosis of systemic fungal infections caused by B. dermatitidis, H. capsulatum and C. immitis

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