Brainscape's Knowledge GenomeTM

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


See full index

Veterinary Virology > Families: Asfarviridae and Iridoviridae > Flashcards

Families: Asfarviridae and Iridoviridae Flashcards

1
Q

What are 3 common names of Asfarviridae?

A
  1. Pesti Porcine Africaine
  2. Pesti Porcina Africana
  3. Maladie de Montgomery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the structure of Asfarviridae virions?

A
  • multiple layers of core
  • internal envelope
  • capsid
  • external envelope
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the genome of Asfarviridae like? Where do they replicate? How do they undergo transcription and mRNA processing?

A

single molecule of linear dsDNA (170-194 kb) with complementary terminal loops (covalently closed ends)

cytoplasm

virus-encoded enzymes

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

What is the host range of Asfarviridae?

A

domestic pigs, wild boar
(African Swine Fever)

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

Is Asfarviridae enveloped or naked? What is the structure of its capsid?

A

enveloped

icosahedral

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

Where is African Swine Fever most commonly a problem?

A

Africa, Europe, Asia

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

There is a huge variation in Asfarviridae virulence. What are the main 3 varients?

A
  1. highly virulent variant: high mortality rate 10-100% within 7-10 days
  2. moderately virulent variant: cause acute viral infections in pigs with high survival rates
  3. low virulent variant: causes seroconversion among affected animals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 4 steps of African Swine Fever virus infection?

A
  1. virus enters cells through clathrin-mediated endocytosis
  2. virus progresses rapidly through endocytosis
  3. replication and assembly occur in cytoplasm
  4. new progeny viruses exit the cells through budding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 2 cycles of African Swine Fever virus infection? In what 2 ways is it transmitted?

A
  • SYLVANTIC: ticks infect wild pigs (boars, wharthogs)
  • DOMESTIC: tick infects domestic pig and can spread to other pigs via direct contact
  • trans-stadial: sequential passage of parasites acquired during one life stage
  • trans-ovarial: from parent to offspring via ovaries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does African Swine Fever virus evade the host immune system?

A

hides within macrophages and RBCs

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

What 4 gross lesions are seen in African Swine Fever?

A
  1. marked hyperemia of legs
  2. bloody mucoid and foamy nasal discharge
  3. large demarcated zone of hyperemia in perineal region
  4. necrotic exudate sloughing from lesion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the 3 classical lesions of African Swine Fever seen in necropsies? What are 2 additional post-mortem lesions?

A
  1. large, dark, friable spleen
  2. large hemorrhagic gastrohepatic LNs
  3. large hemorrhagic renal LNs
  • renal petechial, serosal hemorrhage
  • sub-endocardial hemorrhage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the proper samples collected from pigs to diagnose African Swine Fever?

A
  • swabs (nasal, rectal, oropharyngeal)
  • tissues from freshly dead or slaughtered animal (kidney, liver, spleen, LNs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are 5 laboratory tests used to diagnose African Swine Fever?

A
  1. hemadsorption
  2. viral antigen detection: direct fluorescent antibody test
  3. viral nucleic acid detection: PCR, rtPCR
  4. viral antibody detection in sera: ELISA
  5. seroconversion (convalescent > acute 4x)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the primary control strategies and eradication strategy with African Swine Fever?

A

CONTROL: establish a control area around the infected animal premises, avoid contact between infected and susceptible animals, quarantine and movement restrictions
- infected zone = 3 km
- buffer zone = 2 km
- surveillance zone = >5 km

ERADICATION: depopulation of feral pigs around infected premises, euthanize infected animals and those in contact

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

What makes the development of DNA and recombinant protein vaccines against Asfarviridae difficult?

A

complexity of the virus particle and its ability to modulate host immune response

17
Q

What kind of genome does Iridoviridae have? What are 3 major aspects of its structure?

A

single linear dsDNA (140-300 kbp)

  1. icosahedral capsid
  2. viral core
  3. outer capsid separated by an internal lipid membrane
18
Q

What are the 5 genera of Iridoviridae? What is the sixth unnamed one known as?

A
  1. Iridovirus
  2. Chloriridovirus
  3. Ranavirus
  4. Megalocytivirus
  5. Lymphocystivirus
  6. intraerythrocytic virus of fish and reptiles
19
Q

What does the Ranavirus infect?

A

RBCs

20
Q

What genus of Iridovirus is Red Sea Bream Iridovirus a part of? What are 5 common lesions?

A

Megalocytivirus

  1. lethargy
  2. anemia
  3. branchial hemorrhages
  4. enlarged spleen
  5. cytomegalic macrophages with cytoplasmic inclusions found in the spleen, kidney, intestine, eye, pancreas, liver, heart, gills, and brain
21
Q

How does infection with Red Sea Bream Iridovirus progress? What kind of distribution does it have? How is it transmitted?

A

long-term persistance in hosts, follwed by acute or inapparent infections

worldwide

horizontally

22
Q

What is the mortality of captive fish populations with Red Sea Bream Iridovirus?

A

100%

23
Q

What are 3 major Ranaviruses of importance?

A
  1. Frog virus 3
  2. Ambystoma tigrinum virus
  3. Santee-Cooper virus
24
Q

What is characteristic of frog virus 3 infection? What animals are infected?

A

localized cutaneous hemorrhage and ulceration or more severe systemic disease with edema, hemorrhage, and necrosis in numerous organs

tadpoles (most susceptible) and frogs in North America, Europe, and Asia

25
Q

What species does Ambystoma tigrinum virus infect? When is infection most common?

A

larval and adult salamanders in North America

late summer to early autumn

26
Q

How does environmental temperature play a role in Ambystoma tigrinum virus infection?

A

18 C = death
26 C = survival

(hotter = less serious infection)

27
Q

What Ranavirus causes substantial seasonal loss of wild largemouth bass in lakes in the US? What tissue is most commonly affected?

A

Santee-Cooper Ranavirus

swim bladder - becomes reddened and enlarged, containing a yellow exudate, resulting in moribund fish that float to the surface

28
Q

Vaccines…..

a. damage host cells
b. are only needed once
c. kill viruses
d. stimulate an immune response

A

D

29
Q

Enteroviruses differ from neurotropic viruses mainly in their….

a. type of nucleic acid
b. size
c. capsid shape
d. ability to survive in acidic conditions

A

D

30
Q

All of the following are true EXCEPT:

a. viruses contain DNA or RNA, not both
b. viruses replicate only in living cells
c. viruses use the cell’s biosynthetic machinery to synthesize copied of themselves
d. viral mRNA, tRNA, and ribosomes are used in viral replication

A

D

Veterinary Virology (25 decks)

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