30 - Reoviridae, Birnaviridae

Question 1

Reoviridae

Answer 1

• Etymology: Respiratory enteric orphan
• Morphology:
  
  • ​Segmented dsRNA
  • Icosahedral
  • Double capsid
  • Non-enveloped
• Resistance:
  
  • Strong: ​orthoreo, rota
  • Weaker: orbi, colti
• Biological properties:
  
  • Baltimore III. – viral transcriptase
  • Orbi, Rota: in vitro difficult to cultivate
  • Orthoreo: cytoplasmic inclusion bodies, rounding
• Antigenic properties:
  
  • ​Good antigens
  • Cross reactions +/-
• Diagnosis:
  
  • ​Isolation
  • Experimental animals (Orbivirus genus)
  • IF, ccIEF, IEM (Rotavirus genus)

Question 2

Reoviridae

List the subfamilies and their genera

Answer 2

• Spinareovirinae: (spikes on the surface of the virions)
  
  • ​Orthoreovirus genus
  • Coltivirus genus
• Sedoreovirinae: (no spikes, still surface)
  
  • ​Orbivirus genus
  • Rotavirus genus
  • Sedornavirus genus

Question 3

Reoviridae

Spinareovirinae: Orthoreovirus genus

Answer 3

• Mammilian reoviruses (1-3)
  
  • Pneumoenteritis
  • Euryxen: calves, lambs, foals, dogs, humans, etc.
• Avian reoviruses
  
  • ​Several strains
  • Tenosynovitis

Question 4

Reoviridae

Spinareovirinae: coltivirus genus

Answer 4

• Colorado Tick fever
• Colorado tick fever
  • ​Human fever
  • Rash

Question 5

Reoviridae

Sedoreovirinae: orbivirus genus

Answer 5

• Orbis: circles
• African horse sickness
  
  • ​Oedema
  • Haemorrhage
  • Pneumonia
• Bluetongue
  
  • ​Abortion
  • Cyanosis
  • Oedema
  • Sheep, cattle
• Ibaraki disease
  
  • ​Cattle
  • Abortion
  • Asia
• Epizootic hemorrhagic disease
  
  • ​Deer
  • North America
• Equine encephalosis
  
  • ​Southern Africa

Question 6

Reoviridae

Sedoreovirinae: rotavirus genus

Answer 6

• Rota: wheel
• A, B, C, D, and E species (~serotypes)
• Neonatal enteritits (+ E. coli)
  
  • Calves, piglets, children

Question 7

Reoviridae

Sedoreovirinae: seadornavirus genus

Answer 7

• South Eastern Asia Dodeca RNA virus
• Banna virus
• Kadipiro virus
• Liao Ning virus
• Human: influenza-like illness, encephalitis
• Zoononotic

Question 8

Birnaviridae

Answer 8

• Etymology: bi-RNA
• Morphology:
  
  • ​Segmented (2) dsRNA
  • Icosahedrial capsid
  • Non enveloped
• Resistance: Strong
• Biological properties:
  
  • ​Baltimore III. - viral transcriptase
  • Isolation only in species specific tissue culture (difficult)
  • Virulence variants
• Antigenic properties:
  
  • ​Good antigens
  • No cross reactions
• Diagnosis:
  
  • ​Clinical signs
  • Isolation
  • IF, EM

Question 9

Birnaviridae

List the genera

Answer 9

• Avivirnavirus genus
• Aquabirnavirus genus

Question 10

Birbaviridae

Avibirnavirus genus

Answer 10

• Infectious bursal disease (Gumboro disease)
  
  • Chicken – multiplication in bursa of Fabricius
  • Immunosuppression

Question 11

Birbaviridae

Aquabirnavirus genus

Answer 11

• Infectious pancreatic necrosis - Salmonidae (laks)