33 - Nidovirales (Coronaviridae, Tobaniviridae, Arteriviridae)

Question 1

Nidovirales

Etymology

Answer 1

• Nidus: nest
• Nested set of subgenomic mRNA synthesis for the structural proteins

Question 2

Coronaviridae

Answer 2

• Morphology:
  
  • +ssRNA genome
  • Helical capsid
  • Enveloped
• Resistance:
  
  • Good pH resistance (pH 3-9)
  • Heat labile
• Biological properties:
  
  • Baltimore IV., subgenomic mRNA synthesis
  • Host specific – in vitro too
  • CPE: not characteristic (rounding, lysis)
  • HA: varies (HEV)
• Antigenic properties:
  
  • Relatively good antigens
  • Cross-reactions within genera – „serogroups” (IF, ELISA)
• Diagnosis:
  
  • Isolation (difficult) + IF
  • Clinical signs, IF, IEM
  • Indirect: ELISA, IF (cross-reactions), VN, (HAI)

Question 3

Coronaviridae

List the subfamilies and their genera

Answer 3

• Coronavirinae
  
  • Alphacoronavirus genus
  • Betacoronavirus genus
  • Gammacoronavirus genus
  • Deltacoronavirus genus
• Torovirinae
  
  • Torovirus genus
  • Bafinivirus genus

Question 4

Coronaviridae

Coronavirinae: Alphacoronavirus genus

Answer 4

• Porcine transmissible gastroenteritis virus (TGE)
  
  • Piglets
  • Severe enteritis, diarrhoea, respiratory form
• Porcine epidemic diarrhea virus (ED)
• Feline infectious peritonitis virus (FIP)
  
  • Immunocomplex disease
  • Wet form: ascites, peritonitis
  • Dry form: nephritis, uremia
• Canine coronavirus
  
  • ​Enteritis, diarrhoea
• Human coronaviruses (229E, NL63)
• Bat coronaviruses

Question 5

Coronaviridae

Coronavirinae: Betacoronavirus genus

Answer 5

• Bovine coronavirus
  
  • Winter dysentery, calf diarrhoea
• Porcine hemagglutinating encephalomyelitis virus (HEV)
• Canine respiratory coronavirus
  
  • Kennel cough syndrome
• Human respiratory coronavirus
• Severe acute respiratory syndrome (SARS) virus
  
  • Human pneumonia
  • Surfactant production ↓ - atelectasia

Question 6

Coronaviridae

Coronavirinae: Gammacoronavirus genus

Answer 6

• Avian infectious bronchitis (IB)
  
  • Chicken: respiratory symptoms
  • Hens: egg deformities
• Turkey bluecomb disease
  
  • ​Enteritis, diarrhea
• Duck, Goose, Pigeon, Pheasant coronaviruses

Question 7

Coronaviridae

Coronavirinae: Deltacoronavirus genus

Answer 7

Wild bird (bulbul, trush) coronaviruses

Question 8

Coronaviridae

Torovirinae: Torovirus genus

Answer 8

• Etymology: Torus: base of a column
• Berne virus
  
  • Foal gastroenteritis
• Breda virus
  
  • Calf gastroenteritis
• Chicken, swine, human gastroenteritis

Question 9

Coronaviridae

Torovirinae: Bafinivirus genus

Answer 9

White bream virus

Question 10

Arteriviridae

Answer 10

• Etymology: arteritis
• Morphology:
  
  • ​+ssRNA genome
  • Icosahedral capsid
  • Enveloped
• Resistance: weak
• Biological properties:
  
  • ​Baltimore IV., subgenomic mRNA synthesis

Question 11

Arteriviridae

List the generas

Answer 11

Arterivirus genus

Question 12

Arteriviridae

Arterivirus genus

Answer 12

• Equine arteritis virus (EAV)
  
  • Arteritis – edema, abortion, respiratory signs
  • Stallions may become persistently infected
    
    • They carry the virus in the genital tract, and then shed the virus by the semen
• Porcine reproductive and respiratory syndrome (PRRS)
  
  • (Swine infertility and respiratory syndrome – SIRS)
  • Early abortion – infertility
  • Respiratory signs – cyanosis (blue ear)

Question 13

Tobanviridae

Alt om tobanviridae

Answer 13

• Torovirinae subfamily
  
  • _​_Torovirus genus
    
    • ​Bernevirus
      
      • ​Foal
      • Gastroenteritis
    • Breda virus
      
      • ​Calf
      • Gastroenteritis
    • Chicken-, swine-, human gastroenteritis
• Piscanivirinae subfamily
  
  • _​_Bafnivirus genus
    
    • ​White beam virus
      
      • ​Clinical problems are not known