9. Olds (1st exam - 3)

Question 1

Give two types of genomic NA and their configurations.

Answer 1

• dsDNA, ssDNA — linear or circular
• dsRNA, (-)ssRNA, (+)ssRNA — segmented or non-segmented

Question 2

Give 5 strategies to control viral diseases.

Answer 2

1. Hygiene and sanitation
2. Elimination of vectors
3. Quarantine animals
4. Slaughter animals
5. Passive immunization of animals
6. Chemotherapy in viral diseases
7. Vaccination

Question 3

Class V virus and genomic

Answer 3

• (-)ssRNA
• Bornaviridae, Arenaviridae, Bunyaviridae, Paramyxoviridae, Rhabdoviridae, Orthomyxoviridae, Filoviridae

others?

Question 4

What is Common Vehicle Viral Transmission? Give 2 examples.

Answer 4

1. Blood
2. Fecal contamination of food and water supplies - feco-oral transmission
3. Virus-contaminated meat or bone products

Question 5

3 tests for antiviral antibodies and 3 tests for viral proteins

Answer 5

Antiviral Antibodies
1. ELISA
2. Serum neutralization assays
3. Immunoblotting
4. LFD

**Viral Proteins
**1. LFD
2. PCR

Question 6

Innate and adaptive immunity of the GIT

Question 7

Uses of viral phylogenetic tree in epidemiological studies.

Answer 7

• Sequence data comparison is presented in phylogenetic trees. Phylogenies are tree-like pictorial descriptions of the evolutionary history of a paticular virs species or family (also called evolutionary tree)
• Trees are typically generated based on sequence comparison of
  1. conserved regions
  2. variable regions
  3. whole viral genomes

Question 8

What is the major target of CTL? Draw and label how it detects and destroys its target.

Question 9

Loeffler and Frosch experiment on FMD. How did the two scientists come to the conclusion that the virus causing FMD are ‘filterable agents’?

Answer 9

• The commission on FMD had been set up with the aim of producing a vaccine to prevent the disease, and
• Loeffler and Frosch took lymph fluid from vesicles caused by FMD and proceeded to filter the material through bacteria-proof filter candles
• In the hope that the infectious material would be retained, leaving behind an anti-toxin which could be used to confer passive immunity to healthy animals.
• They were amazed when inoculated calves developed characteristic disease symptoms, and they were able to show that something had passed through the filter candles
• which was able to multiply in the infected animals.