(08) Picornaviridae & Reoviridae Flashcards
1
Q
(Viruses with dsRNA)
- What are two groups?
- What are three types in Reoviridae?
A
- reociridae and birnaviridae
- rotaviruses
- bluetongue virus
- african horse sickness
2
Q
(General Characteristics of Reoviruses)
- enveloped?
- shape?
- How many capside layers?
- RNA segmented?
- where do they replicate?
A
- non-enveloped
- spherical
- 3
- yes (can easily recombine)
- cytoplasm (see inclusion bodies in cytoplasm)
3
Q
(Rotavirus Structure)
- Outer capsid protein made up of what two proteins? What do they do?
- How many serogroups? most common serogroup?
- RNA composed of how many segments? make how many proteins?
A
- VP4 (attachment receptor)
- seven; serogroup A
- 11, 12
4
Q
(General Characteristics)
- Orbiviruses are what kind of viruses? Seen in a circumscribed geographical area as the what?
- What kind of viruses are rotaviruses?
A
- arboviruses, vector
- rotaviruses (cause scours in newborns - all domestic animal and birds have one)
5
Q
A
B
6
Q
(Picornaviridae)
- how big?
- What is the important genera?
A
- one of the smallest
- apthovirus (causes foot and mouth disease)
7
Q
(Picornaviridae)
(General Characteristics)
- enveloped or non?
- RNA single or double? + or - sense?
- How many capside layers?
- Stability in pH?
- Replication occurs where?
- How is virus spread/released?
A
- non
- single; + (can make copies right away)
- one
- varied (aptho unstable below 7) - Entero/cardio stable at PH 3
- cytoplasm
- cell lysis and virus release
8
Q
know what kinds of disease these cause
also notice the size thing - supposedly something wronge there
A
9
Q
(Rotavirus)
- Major cuase of what?
- What levels of titer excreted in feces?
- Inactivated by what?
- How sensitive to chlorination?
A
- neonatal diarrhea
- high (10^11/gm)
- phenolic disinfectants
- relatively insenitive
10
Q
1-3. What three viruses cause diarrhea in neonates?
A
- rotavirus
- coronavirus
- BVDV
11
Q
(Susceptibily of neonates to Rotaviruses and Coronaviruses)
- Which of the two lasts longer?
- Note the thing about the colostral antibodies…
- Is mucosal or systemic antibody more important?
A
- coronaviruses
- mucosal
12
Q
(Maintenance of Rotaviruses in Populations)
- stable in envrionment?
- persistence and periodic shedding? (what does this cause)?
A
- yes
- yes; subclinical infection in calves and adults
13
Q
(Rotavirus Pathogenesis)
- Usually seen in 1-8 weeks olds. What is the incubation period?
- Infection leads to destruction of what?
A
- 16-24 hours
- epithelial cells (at the apices of villi in small intestines) - this leads to poor absorption and then diarhhea
14
Q
(Effect of rate of enterocyte replacement on disease (by rotavirus))
- Rate is low in young calves - does this make them more or less susceptible?
- later on… competition between what and infection?
A
- more
- replacement (better ability to replace causes less disease)
15
Q
(Rotavirus infection of intestinal cells)
- How long is incubation?
- Death is the result of what?
A
- short incubation (~12 hours)
- dehyration and secondary bacterial infection
(just look at this slide a little)