Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MTAP FIRST SEM 2024-2025 > VIROLOGY- INTRO > Flashcards

VIROLOGY- INTRO Flashcards

1
Q

A submicroscopic, obligate intracellular parasite, among the smallest of all infectious agents, capable of infecting any animal, plant, or bacterial cell.

A

virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is essential for the survival of viral infectious agents?

A

Their ability to infect and reside in a living organism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where are viruses found?

A

In every ecosystem.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Can viruses replicate without a living host cell?

A

No, they are strict obligate intracellular parasites and cannot replicate without a living host cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Major changes in viral genomes that result in novel viral antigens.

A

antigenic shift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The specificity of virus types, where each virus has a limited number of hosts it can infect.

A

viral tropism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The emergence of a new viral disease across a very large geographic region (worldwide) with prolonged human-to-human transmission.

A

Pandemic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Minor changes in viral genomes that occur infrequently.

A

antigenic drift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the term for a virus that emerges as a completely new entity?

A

A completely new or “novel” virus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the two or three parts that make up a virus particle (virion)?

A

-Inner nucleic acid core (RNA or DNA)
-Protein coat (capsid)
-Lipid-containing envelope (in some larger viruses)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

It surrounds and protects the nucleic acid.

A

protein coat (capsid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How are enveloped viruses typically transmitted?

A

By direct contact: respiratory, sexual, or parenteral contact.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why are “naked” viruses resistant to environmental factors?

A

Because they do not have an envelope, making them very stable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

are extensions from the surface of the virus.

A

glycoprotein spikes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The nucleic acid genome surrounded by a symmetric protein coat.

A

nucleocapsid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

It encodes the proteins required for viral penetration, transmission, and replication.

A

Nucleic acid genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What determines the mechanism for viral replication?

A

The structure of the viral genome (e.g., (+) sense-strand RNA, (–) sense-strand RNA, and DNA genomes).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

protects the viral genome and is responsible for the tropism to specific cell types in naked viruses.

A

Viral capsid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

It is responsible for viral entry into the host cell.

A

lipid envelope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

It lies between the envelope and the nucleocapsid and may have enzymatic activities or biological functions related to infection, such as inhibition of host-cell transcription

A

Matrix protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

very susceptible to drying and destruction in the environment

A

Enveloped viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Typically are composed of repeating structural subunits referred to as?

A

Capsomeres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Because of their stability, they are typically transmitted by the fecal-oral route

A

“Naked” viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What factors influence specimen selection for viral detection?

A

The specific disease syndrome, viral agents suspected, and time of year.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When should specimens for viral detection be collected?

A

As early as possible after the onset of symptomatic disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How can the recovery and detection of viral agents be enhanced?

A

By using validated devices or containers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which type of specimen is superior for recovering viruses: nasopharyngeal aspirates, throat swabs, or nasopharyngeal swabs?

A

Nasopharyngeal aspirates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

For which viruses are throat swabs acceptable for recovery?

A

Enteroviruses, adenoviruses, and HSV.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which specimens are preferred for the detection of RSV, influenza, and parainfluenza viruses?

A

Nasopharyngeal swab or aspirate specimens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Are all respiratory specimens acceptable for culture of most viruses?

A

Yes,all respiratory specimens are acceptable for culture of most viruses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What specimens are excellent for detecting viruses that infect the lower respiratory tract?

A

Washings and lavage fluid collected during bronchoscopy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Which viruses are especially detected using bronchial and bronchoalveolar washes?

A

Influenza viruses and adenoviruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What specimens are used to detect rotavirus, enteric adenoviruses (serotypes 40 and 41), and enteroviruses?

A

Stool and rectal swabs of fecal specimens.

30
Q

Which is preferable for rotavirus and enteric adenovirus testing: stool specimens or rectal swabs?

A

Stool specimens.

31
Q

When are rectal swabs acceptable for detecting enteroviruses?

A

In patients suspected of having an enteroviral disease, such as aseptic meningitis.

32
Q

What should be done with a rectal swab after collection?

A

It should be placed in appropriate transport media.

33
Q

Which viruses can be detected in urine?

A

Mumps, rubella, measles viruses, polyomaviruses, and adenovirus can be detected in urine

33
Q

How much stool is sufficient and preferred for rotavirus and enteric adenovirus detection?

A

Five to ten mL of freshly passed diarrheal stool or stool collected in a diaper from young infants

34
Q

What is the recommended urine specimen volume for improved virus recovery?

A

A minimum specimen volume of 10mL from a clean-catch first morning urine

35
Q

How can viral recovery be increased in urine specimens?

A

Viral recovery may be increased by processing multiple (two or three) specimens in parallel

36
Q

What techniques improve virus recovery from urine specimens?

A

-improved by centrifugation or filtering to remove contaminants

-neutralizing the pH with a 7.5% solution of sodium bicarbonate

37
Q

Which viruses can be detected in vesicular lesions of the skin and mucous membranes?

A

Enteroviruses, HSV, VZV, and in rare cases CMV or pox viruses can be detected in these lesions

38
Q

What is the purpose of a Tzanck smear in viral detection?

A

used for the detection of HSV or VZV in cutaneous vesicles when PCR testing is not available.

39
Q

What are some examples of sterile body fluids other than blood?

A

Cerebrospinal fluid (CSF), pericardial fluid, and pleural fluid.

40
Q

Which viruses can be found in cerebrospinal fluid (CSF)?

A

Enteroviruses, herpes simplex virus (HSV), varicella-zoster virus (VZV), influenza viruses, and cytomegalovirus (CMV).

41
Q

Can pericardial and pleural fluids contain viruses?

A

Yes, they can contain enteroviruses, HSV, VZV, influenza viruses, or CMV.

42
Q

is used primarily to detect CMV; HSV, VZV, enteroviruses, and adenovirus occasionally may be encountered

A

Viral culture of blood

43
Q

What is CMV viremia associated with?

A

Peripheral blood leukocytes.

44
Q

How much anticoagulated blood is needed for viral culture?

A

Five to ten mL

45
Q

What types of anticoagulated blood are acceptable for CMV detection?

A

Heparinized, citrated, or ethylenediaminetetraacetic acid (EDTA) anticoagulated blood.

46
Q

Which type of anticoagulated blood should be used when considering other viruses?

A

Citrated blood.

47
Q

What can serum be used for in blood tests?

A

Serologic tests and nucleic acid assays.

48
Q

How should bone marrow for virus detection be handled?

A

It should be added to a sterile tube with anticoagulant.

49
Q

What types of anticoagulants are acceptable for bone marrow virus detection?

A

Heparin, citrate, or EDTA anticoagulants.

50
Q

How are bone marrow specimens collected?

A

By aspiration

51
Q

Which virus is an exception to the rule that most viruses are detected more readily from sites other than bone marrow?

A

Parvovirus B19.

52
Q

Which viruses commonly infect the lungs and can be detected in tissue specimens?

A

CMV, influenza virus, adenovirus, and sin nombre virus.

53
Q

What type of tissue is preferred for nucleic acid assays?

A

Fresh tissue.

53
Q

Which virus commonly infects the gastrointestinal tract and brain that can be detected in tissue specimens?

A

Herpes simplex virus (HSV) and Cytomegalovirus (CMV).

54
Q

How are tissue specimens typically collected?

A

During surgical procedures.

55
Q

Can formalin-fixed and paraffin-embedded tissues be used for virus detection?

A

Yes, but they must undergo deparaffinization and extraction first.

56
Q

Which viruses are often detected using genital specimens?

A

Herpes simplex virus (HSV) and human papillomavirus (HPV).

57
Q

should be used for ulcerations and placed in appropriate viral transport media

A

Genital swabs

58
Q

How cervical specimens should be collected?

A

Using a swab or brush and placing them in viral transport media.

59
Q

What types of devices are appropriate for nucleic acid testing of cervical specimens?

A

Most manufactured endocervical or liquid-based cytology devices.

60
Q

When should the convalescent serum specimen be collected?

A

A minimum of 2 to 3 weeks after the acute specimen

61
Q

How much serum is typically collected for antibody testing?

A

3 to 5 mL of serum collected by venipuncture.

62
Q

What should be done with specimens for viral isolation to prevent degradation?

A

They should not be allowed to sit at room or higher temperature and should be kept cool (4°C).

63
Q

What should be done if there is a delay in transporting specimens for viral isolation?

A

The specimen should be refrigerated, not frozen, until processed.

64
Q

Within what time frame should specimens ideally be processed?

A

Within 12 to 24 hours of collection.

65
Q

How should specimens be stored if they need to be held for several days before processing?

A

Up to 5 days at 4°C; for 6 days or longer, at –20°C, preferably –70°C.
Flashcard 6:

66
Q

What should be done to specimens before freezing them?

A

They should first be diluted or emulsified in viral transport medium.

67
Q

Which types of swabs are acceptable for specimen collection?

A

Most types of synthetic swabs, such as rayon and Dacron.

68
Q

Which types of swabs are not recommended for specimen collection?

A

Swabs with cotton tips and wooden shafts.

69
Q

What should be done with swab specimens before transport to the laboratory?

A

They should be emulsified in viral transport medium, especially if transport will occur at room temperature and requires longer than 1 hour.

70
Q

is not acceptable for the culture-based detection of HSV

A

Calcium alginate.

71
Q

What are some examples of viral transport media?

A

-Stuart’s medium,
-Amie’s medium,
-Leibovitz-Emory medium,
-Hanks’ balanced salt solution (HBSS),
-Eagle’s tissue culture medium,
-and the commercially available M4, M5, and universal transport media.

72
Q

How should respiratory, rectal, and stool specimens be maintained?

A

In modified Stuart’s medium, modified HBSS, or Leibovitz-Emory medium containing antimicrobials.

73
Q

How should blood for viral culture be transported?

A

In a sterile tube containing anticoagulant, refrigerated at 4°C until processed.

74
Q

Serum can be stored for hours or days at ____
or for weeks or months at ____ or lower
before testing

A

4°C

–20°C

75
Q

Where should viral specimens be processed whenever possible?

A

In a Biological Safety Cabinet (BSC).

76
Q

What is required if there is a delay in processing fluid specimens?

A

They should be diluted in a transport medium (1:2-1:5) before storage.

MTAP FIRST SEM 2024-2025 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions