MYCOVIRO - CH 59 Book Pt 2

Question 1

Vaginal Samples

-transported to lab within ? hrs using culture transport swabs

Answer 1

24

Question 2

Vaginal Samples

-transported to lab within 24 hrs using __

Answer 2

culture transport swabs

Question 3

vaginal samples: both __ and __ agars be plated

Answer 3

selective and inhibitory

Question 4

vaginal samples must be screened for __, incubated at 30C for 7 days

Answer 4

yeasts

Question 5

vaginal samples must be incubated at (temp and how many days)

Answer 5

30C for 7 days

Question 6

what urine sx is unacceptable for culture

Answer 6

24-hr urine

Question 7

urine sample media must contain what ?

Answer 7

antibacterial agents

Question 8

All tissues must be processed before culturing by: (2)

Answer 8

• Mincing

* Or placement in high speed lab blender

Question 9

express the cytoplasmic contents of cells using pressure from the action of rapidly moving metal paddles

Answer 9

stomacher lab blender

Question 10

what specimen may be placed directly onto the surface of appropriate culture media

Answer 10

BM

Question 11

For optimal recovery, a battery of media should be used:

2

Answer 11

• Media with and without cycloheximide

* Media with and without antibacterial agent (not necessary if specimen is from a sterile site)

Question 12

Agar plates – preferred because (3)

Answer 12

• Provide better aeration
• Larger surface area for better isolation of colonies
• Greater ease of handling

Question 13

agar tends to dehydrate during extended incubation period

–minimized using: ??

Answer 13

culture dishes containing at least 40 mL agar and placing them in a humidified incubator

Question 14

ADV OF SCREW-CAPPED CULTURE TUBES

Answer 14

• Easily stored
• Require less space for incubation
• Easily handled
• Lower dehydration rate
• Less hazardous

Question 15

DISADV OF SCREW-CAPPED CULTURE TUBES

Answer 15

• Poor colony isolation
• Reduced SA
• Tendency to promote anaerobiosis

Question 16

if using screwcapped culture tubes, after inoculation, must be placed in a horizontal position for at least ??? hours to allow the specimen to absorb the agar surface and avoid settling at the bottom of tube

Answer 16

1-2

Question 17

?? tubes unsatisfactory for fungal cultures

Answer 17

cotton-plugged tubes

Question 18

cultures should be examined at least how many times weekly during incubation

Answer 18

3x

Question 19

– added to any media that contain or lack antibiotics

• if it is included, a medium w/o it must also be used
  
  • partially or completely inhibits…

Answer 19

Cycloheximide

Question 20

– recommended method for direct microscopic examination

Answer 20

KOH preparation

Question 21

• better than KOH preparation
• slides are observed using 1) fluorescent microscopy (optimal because fungal cells fluoresce) or 2) bright field microscopy

Answer 21

Calcoflour white stain

Question 22

Serology testing - may be useful for (4, CHAB)

Answer 22

• Cryptococcus
• Blastomyces
• Histoplasma
• Aspergillus

Question 23

– useful but not for immunocompromised patients (incapable of producing a measurable humoral response)

Answer 23

Antibody testing

Question 24

– sensitive method, difficult to perform and interpret

• requires a delay in testing that extends from exposure to onset of symptoms
• detection of antibody can take 2 to 3 months
• cross reactions with other fungal antibodies may be a problem

Answer 24

Complement fixation (CF)

Question 25

– simple, cost-effective procedure - 100% specific, relatively insensitive, not used as a screening tool - requires 2-3 weeks to be positive

Answer 25

Immunodiffusion testing

Question 26

– frequently negative in immunocompromised patients especially early in the infection

Answer 26

Enzyme immunoassays

Question 27

- not accepted as a routine diagnostic tool in mycology

Answer 27

Molecular Detection

Question 28

– biophysical method that reduces time required to specifically identify fungal organisms

Answer 28

MALDI-TOF

Question 29

MALDI-TOF MEANING

Answer 29

Matrix-Assisted Laser Desorption Ionization

Question 30

For Yeast ID Many automated and semiautomated commercial systems have been designed with WHAT tests because C and N source differences are key to yeast differentiation)

Answer 30

assimilation and fermentation

Question 31

o – differentiates yeast presumptively

Answer 31

Chromogenic agar

Question 32

ID factor Most helpful when a mold culture is examined

Answer 32

Growth rate

Question 33

– form mature colonies in 11 to 21 days

Answer 33

slow growers

Question 34

– 6 to 10 days

Answer 34

Intermediate-growers

Question 35

– 5 days or less

Answer 35

Rapid-growers

Question 36

– various elevations on agar plate

Answer 36

• Colony topography

Question 37

Colony topography | furrowed or convoluted

Answer 37

verrucose

Question 38

Colony topography | slightly raised in the center

Answer 38

umbonate

Question 39

Colony topography | – furrows radiate out from the center

Answer 39

rugose

Question 40

colony texture | loose, high aerial mycelium

Answer 40

cottony

Question 41

colony texture | low aerial mycelium resembling a velvet cloth

Answer 41

velvety

Question 42

colony texture | smooth surface with no aerial mycelium

Answer 42

glabrous

Question 43

colony texture | – dense, powdery, like sugar granules

Answer 43

granular

Question 44

colony texture | high aerial mycelium like slightly matted down

Answer 44

wooly

Question 45

o Fungi Preparation for Microscopic Examination (4)

Answer 45

* Cellophane (Scotch) tape preparation – traditional; easy and quick * Wet mount * Tease mount * Microslide culture method

Question 46

Fungi Preparation for Microscopic Examination – traditional; easy and quick

Answer 46

Cellophane (Scotch) tape preparation

Question 47

Fungi Preparation for Microscopic Examination | used when greater detail of morphology is required

Answer 47

• Microslide culture method

Question 48

hyphae type | curved freely branching, antler-like

Answer 48

antler hyphae

Question 49

hyphae type | – enlarged, club-shaped

Answer 49

Racquet hyphae

Question 50

hyphae type | produced by some dermatophytes; coiled corkscrewlike

Answer 50

spiral hyphae

Question 51

type of hyphae common in dermatophytes

Answer 51

spiral

Question 52

asci contains how many ascospores

Answer 52

4-8

Question 53

Types of Conidia (both types not specific)– small, unicellular, round, elliptical or pyriform -may be born directly on the side of a hyphal strand or at the end of a conidiophore

Answer 53

Microconidia

Question 54

Types of Conidia (both types not specific) large, multiseptate, club or spindle shaped -borne on a short to long conidiophore -may be smooth or rough walled

Answer 54

Macroconidia

Question 55

– pinching off | -manner by which conidia are freed from their point of attachment

Answer 55

Abstriction

Question 56

– formed directly from the hyphae by fragmentation through the points of septation -mature: square, rectangular, barrel-shaped, thick-walled cells

Answer 56

Arthroconidia

Question 57

– round, thick-walled spores formed directly from differentiation of hyphae in which there is a concentration of protoplasm and nutrient material -resistant resting spores

Answer 57

Chlamydoconidia (chlamydospores)

Question 58

-may be intercalary (w/in hyphae) or terminal (end of hyphae)

Answer 58

Chlamydoconidia (chlamydospores)

Question 59

Chlamydoconidia (chlamydospores) within hyphae

Answer 59

intercalary

Question 60

Chlamydoconidia (chlamydospores) at end of hyphae

Answer 60

terminal

Question 61

o If a laminar flow BSC is used, a BSC with??? not necessary.

Answer 61

gloves

Question 62

• Yeast cultures may be handled on a __

Answer 62

bench top

Question 63

??? is suitable for decontaminating a loop used to transfer yeast cultures

Answer 63

Eletric incinerator or gas flame

Question 64

• Cultures of organisms suspected of being pathogens should be??? to prevent laboratory contamination and should be autoclaved as soon as definitive ID is made.

Answer 64

sealed with tape