18: reo, birna

Question 1

Reoviridae:

- Subfamilies, genera:

Answer 1

• Spinareovirinae (6 genus, 35 sp.): Orthoreo-, Coltivirus genus
• Sedoreovirinae (9 genus, 49 sp.): Orbi-, Rota- Seadornavirus g.

Question 2

Reoviridae:

• Morphology
• Biological properties
• Antigenic properties
• Diagnosis

Answer 2

Morphology:
- segmented (10-12) dsRNA
- ~70nm icosahedral, double capsid
- non enveloped
Resistance: Orthoreo, Rota: strong (56°C, pH 3)
	Orbi, Colti: weaker

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 (Orbi)
• IF, ccIEF, IEM (Rota)

Question 3

Orthoreovirus genus:

Answer 3

(Reoviridae, Spinareovirinae)

• Mammalian reoviruses (1-3)
• -> pneumoenteritis
• -> euryxen: calves, lambs, foals, dogs, humans, etc.
• Avian reoviruses
• -> several strains
• -> tenosynovitis
• -> ranting-stunting syndrome, PEMS, „helicopter disease”

Question 4

Coltivirus genus:

Answer 4

(Reoviridae, Spinareovirinae)

• Colorado tick fever – human fever, rash

Question 5

Orbivirus genus:

Answer 5

(Reoviridae, Sedoreovirinae)

• 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 – South Africa

Question 6

Rotavirus genus:

Answer 6

(Reoviridae, Sedoreovirinae)

• A, B, C, D, and E species (~serotypes)
• neonatal enteritis (+ E. coli) – calves, piglets, children

Question 7

Seadornavirus genus:

Answer 7

(Reoviridae, Sedoreovirinae)
South eastern Asia dodeca RNA virus
- Banna virus, Kadipiro virus, Liao Ning virus
- human – influenza-like illness, encephalitis
- zoononotic?

Question 8

Birnaviridae:

- genera

Answer 8

Avibirna-, Aquabirnavirus genus

Question 9

Birnaviridae:

• Morphology
• Biological properties
• Antigenic properties
• Diagnosis

Answer 9

Morphology:
- segmented (2) dsRNA
- ~60nm icosahedral capsid
- non enveloped
Resistance: strong (56°C, pH 3)

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 10

Avibirnavirus genus:

Answer 10

(Birnaviridae)

• Infectious bursal disease (Gumboro disease)
• -> chicken – multiplication in bursa of Fabricius
• -> immunosuppression

Question 11

Aquabirnavirus genus:

Answer 11

(Birnaviridae)

- Infectious pancreatic necrosis - Salmonidae