MYCOVIRO - CH 60 of book part 4

Question 1

broad based yeast

Answer 1

Blastomyces dermatitidis

Question 2

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

Answer 2

Blastomyces dermatitidis

Question 3

“prickly state” – tufts of hyphae projects upward

Answer 3

Blastomyces dermatitidis

Question 4

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

Answer 4

Blastomyces dermatitidis

Question 5

direct exam of sputum or lung aspirate

Answer 5

Coccidioides immitis

Question 6

observe non-budding thick-walled spherule

Answer 6

Coccidioides immitis

Question 7

spherule either contains granular material or endospores

Answer 7

Coccidioides immitis

Question 8

alternate arthroconidia – arthroconidia separated by disjunctor cells

Answer 8

Coccidioides immitis

Question 9

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

Answer 9

Coccidioides immitis

Question 10

wet preparation: sterile saline + petrolatum, incubated overnight

Answer 10

Coccidioides immitis

Question 11

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

Answer 11

Coccidioides immitis

Question 12

delicate cobweb-like growth

Answer 12

Coccidioides immitis

Question 13

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

Answer 13

Coccidioides immitis

Question 14

fluffy white, greenish discoloration on blood agar

Answer 14

Coccidioides immitis

Question 15

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

Answer 15

Coccidioides immitis

Question 16

Histoplasma capsulatum

- Stain and specimen ??

Answer 16

Wright- or Giemsa-stained bone marrow specimens

Question 17

found intracellularly in mononuclear cells as small round yeast cells
o

Answer 17

Histoplasma capsulatum

Question 18

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

Answer 18

Histoplasma capsulatum

Question 19

to remove contamination in H. capsulatum:

Answer 19

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

Question 20

recovered from blood culture within 8 days

Answer 20

Histoplasma capsulatum

Question 21

white, fluffy mold that turns brown to buff with age

tufts of hyphae project upward

Answer 21

Histoplasma capsulatum

Question 22

mariner’s wheel, mickey mouse cap

Answer 22

Paracoccidioides brasiliensis

Question 23

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

Answer 23

Paracoccidioides brasiliensis

Question 24

test for definitive identification of Paracoccidioides brasiliensis

Answer 24

Exoantigen test:

Question 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)

Answer 25

Penicillium marneffei

Question 26

observe small, yeastlike cells with septa; reveals annelid formation

Answer 26

Penicillium marneffei

Question 27

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

Answer 27

Penicillium marneffei

Question 28

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

Answer 28

Sporothrix schenckii

Question 29

small, round to cigar-shaped yeast cells

Answer 29

Sporothrix schenckii

Question 30

stained using periodic acid-Schiff (PAS) method

Answer 30

Sporothrix schenckii

Question 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)

Answer 31

Sporothrix schenckii

Question 32

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

Answer 32

Sporothrix schenckii

Question 33

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

Answer 33

SERODIAGNOSIS