Testing of Viruses

Question 1

Conventional cell culture cell monolayer

Answer 1

Growing cell monolayer (single confluent layer) on plastic or glass tube

Question 2

Conventional cell culture incubation conditions

Answer 2

Roller drum, tilted 5-7 degrees, revolving at 0.5-1 rpm at 35-37°C for 1 to 4 weeks

Question 3

Advantage of conventional cell culture

Answer 3

Can detect different viruses in one cell culture

Question 4

Disadvantage of conventional cell culture

Answer 4

Long, laborious process

Question 5

EDTA/Heparin blood handling

Answer 5

Separate buffy coat

Question 6

CSF specimen handling

Answer 6

Inoculate 1 mL directly

Question 7

Feces/Rectal swab handling

Answer 7

Place in 2 mL VTM → Vortex → Centrifuge → Inoculate

Question 8

NPS/OPS/Sputum/Respiratory washings handling

Answer 8

Dilute with VTM

Question 9

Tissue specimen handling

Answer 9

Mince with scalpel/scissors → Gently grind → Suspend in VTM → Centrifuge → Inoculate

Question 10

Swab/Fluid specimen handling

Answer 10

Emulsify in VTM

Question 11

Urine specimen handling (clear)

Answer 11

Inoculate directly

Question 12

Urine specimen handling (turbid)

Answer 12

Centrifuge → Inoculate

Question 13

Genital/Skin (Vesicle fluid/Scrapings) specimen handling

Answer 13

Emulsify in VTM

Question 14

Urine cell culture for adenovirus

Answer 14

HDF, HEp-2

Question 15

Major cell culture types

Answer 15

PMK, HDF, HEp-2

Question 16

Genital/Skin cell culture

Answer 16

HDF

Question 17

Cell culture tube procedure

Answer 17

Absorption (12-24 hours) → Maintenance tube (replace 1-2x/week) → Incubation (5-28 days)

Question 18

Freezing in cell culture

Answer 18

Remove old medium → Add fresh culture medium

Question 19

Passaging or Splitting

Answer 19

Remove cells from surface, dilute, place into new container

Question 20

Blind Passage

Answer 20

Pass cells and fluid to a SECOND cell culture tube

Question 21

Cytopathic Effect

Answer 21

Visual morphologic changes in cells associated with specific virus infection

Question 22

Objective for observing cytopathic effects

Answer 22

Inverted phase contrast microscope (objective stage)

Question 23

Adenovirus in HEp-2 medium

Answer 23

Large rounding aggregates

Question 24

Confirming Adenovirus infection

Answer 24

Fluorescent antibody

Question 25

RSV in HEp-2 medium

Answer 25

Syncytia of cells

Question 26

Cytomegalovirus in HDF medium

Answer 26

Very slow discrete small foci of rounded cells

Question 27

Varicella-Zoster in HDF medium

Answer 27

Very slow rounded, swollen, refractile cells

Question 28

Herpes simplex virus in HEp-2, HDF, A549, RK medium

Answer 28

Rapid rounded, swollen, refractile cells

Question 29

Enterovirus in PMK medium

Answer 29

Refractile angular or tear-shaped cells

Question 30

Rhinovirus in HDF and PMK medium

Answer 30

Labile, HDF: Refractile rounding of cells, PMK: Refractile angular or tear-shaped cells

Question 31

Quantitation of Cytopathic Effect Uninfected monolayer

Answer 31

Negative

Question 32

Quantitation of Cytopathic Effect: Atypical alteration of monolayer involving few cells

Answer 32

Equivocal (±)

Question 33

Quantitation of Cytopathic Effect 1-25% of monolayer has CPE

Answer 33

1+

Question 34

Quantitation of Cytopathic Effect 25-50% of monolayer has CPE

Answer 34

2+

Question 35

Quantitation of Cytopathic Effect 50-75% of monolayer has CPE

Answer 35

3+

Question 36

Quantitation of Cytopathic Effect 76-100% of monolayer has CPE

Answer 36

4+

Question 37

R-mix shell vial for respiratory viruses (influenza)

Answer 37

1 type of Vx specific Ab

Question 38

Rapid virus detection

Answer 38

1-2 days instead of 5-28 days

Question 39

Disadvantage of shell vial cell culture

Answer 39

Can ONLY detect 1 type of virus per shell vial

Question 40

Provides the most sensitive method and is usually the more preferred technique compared to other alternative testing methods

Answer 40

NAAT

Question 41

Preferred testing method for common viruses Coronavirus Enterovirus Parechovirus Herpes virus

Answer 41

NAAT

Question 42

Preferred testing method for common viruses Adenovirus Influenza virus Parainfluenza virus RSV Varicella-Zoster virus Rotavirus Norovirus/Norwalk

Answer 42

NAAT, Antigen test

Question 43

Preferred testing method for common viruses Arbovirus, Cytomegalovirus, EBV, Parvovirus B19

Answer 43

NAAT, Antibody test

Question 44

Preferred testing method for common viruses= Hepatitis B Hepatitis D, HIV

Answer 44

NAAT, Antibody, antigen testing

Question 45

Preferred testing method for common viruses= Filovirus (Ebola) Arenavirus (LCMV, Lassa virus) Hantavirus Hepatitis A Hepatitis C Hepatitis E HTLV Rabies virus

Answer 45

Antibody test