31 - Picornaviridae, Picornavirales, Caliciviridae, Astroviridae

Question 1

Picornaviridae

Answer 1

• Etymology: Pico: RNA
• Morphology:
  
  • ​+ssRNA genome
  • Icosahedral capsid
  • Non enveloped
• Resistance: Generally good
  
  • 56ºC, pH3: enterovirus, hepatovirus, teschovirus
  • Weaker: cardiovirus, rhinovirus
• Biological properties:​
  
  • Baltimore IV.: genome ~ mRNA – short replication cycle
  • Single polyprotein processed by viral enzymes
  • Generally stenoxen (except Aphtho) – in vitro too
  • CPE: rounding, rhexis
• Antigenic properties:
  
  • ​Good antigens
  • Sereotypes - no cross protection
  • Transcapsidation
• Diagnosis:
  
  • ​Isolation
  • IF, CF (FMS)
  • Indirect: VN, CF, AGID, ELISA

Question 2

Picornaviridae

List the different genera

Answer 2

17 genera

• Enterovirus genus
• Teschovirus genus
• Hepatovirus genus
• Avihepatovirus genus
• Tremovirus genus
• Cardiovirus genus
• Aphtovirus genus
• Erbovirus genus
• Parechovirus genus
• Kobuvirus genus

Question 3

Picornaviridae

Enterovirus genus

Answer 3

• Entero: intestine
• Swine vesicular disease (porcine picornavirus 9)
  
  • Swine - clinical signs: FMD
  • Antigenic structure: coxakie B5
• Bovine enterovirus (1-2)
• Human poliovirus (1-3): polioencephalomyelitis
• Human coxsackie virus A (1-24) and B (1-6)
  
  • Aseptic meningitis; hand, foot, and mouth disease
• Human echovirus (1-33) (enteric cytophatic human orpahn)
• Rhinoviruses (rhinos: nose)
  
  • Common cold
  • Thermosensitive mutants
• Simian enteroviruses

Question 4

Picornaviridae

Teschovirus genus

Answer 4

• Teschen
• Porcine teschovirus 1: teschen/talfan disease​
  
  • Polyomyelitis
  • Paralysis
• Porcine teschovirus 2-8, 10-1: apathogen

Question 5

Picornaviridae

Hepatovirus genus

Answer 5

• Hepatos: liver
• Hepatitis A
  
  • ​Human - hepatitis, icterus
• Simian hepatitis A

Question 6

Picornaviridae

Tremovirus genus

Answer 6

• Tremor
• Avian encephalomyelitis
  • ​Chicken
  • Epidemic tremor

Question 7

Picornaviridae

Cardiovirus genus

Answer 7

• Cardia: heart
• Encephalomyocarditis virus
  • ​Euryxen
  • Reservoir: rodents
  • Swine, horse, human, elephants

Question 8

Picornaviridae

Aphthovirus genus

Answer 8

• Aphtha: vesicles
• Foot and mouth disease
  
  • ​Serotypes: O, A, C, SAT-1, SAT-2, SAT-3, Asia-1
  • Euryxen: ruminants, swine, (human)
  • Vesicles: oral cavity, hoofs, enteric mucosa
  • Myocarditis
• Equine rhinitis A

Question 9

Picornaviridae

Erbovirus genus

Answer 9

• Equine rhinitis B
• Equine rhinitis B

Question 10

Picornaviridae

Parechovirus genus

Answer 10

• Para: echo
• Human, rodent parechoviruses
  • ​Enteritis or apathogen

Question 11

Picornaviridae

Kobuvirus genus

Answer 11

• Kobu: japanese for hump, knob
• Aichi virus
  • ​Human enteric disease

Question 12

Picornaviridae

Avihepatovirus geuns

Answer 12

• Avis: bird
• Hepato: liver
• Duck hepatitis A or 1

Question 13

Picornaviridae

List the unassinged picornaviruses

Answer 13

• Equine picornaviruses
• Turkey hepatitis
• Guineafowl enteritis
• Avian entero-like viruses
• Sea-animal enteroviruses

Question 14

Picornavirales

Answer 14

• A proposed new order
• Viruses with similar morphology
• Morphology:
  
  • Icosahedral capsid
  • No envelope
  • +ssRNA
  • Differences in genome organization, host spectrum
• Dicistroviridae
  
  • ​Aparavirus
    
    • ​Acute bee paralysis virus
    • Israeli acute pralysis virus
    • Kashmir bee virus
  • Cripavirus
    
    • ​Black queen cell viruses
• Iflaviridae
  
  • Iflavirus
    
    • ​Sacbrood virus
    • Deformed wing virus

Question 15

Caliciviridae

Answer 15

• Etymology: calix: cup
• Morphology:
  
  • ​+ssRNA genome
  • Icosahedral capsid
  • Non enveloped
• Resistance: good
• Biological properties:
  
  • ​Baltimore IV. – subgenomic mRNAs
  • Stenoxen - propagation in species specific tissue cultures → RHD: in vitro not possible to propagate
  • CPE: lysis
• Antigenic properties: good antigens
• Diagnosis:
  
  • ​Clinical signs
  • Isolation if possible
  • AGID, IF, EM
  • Serology: AGID, IIF

Question 16

Caliciviridae

List the different genera

Answer 16

• Vesivirus genis
• Lagovirus genis
• Norovirus genis
• Sapovirus genus

Question 17

Caliciviridae

Vesivirus genus

Answer 17

• Etymology: Vesicular exanthema
• Vesicular exanthema of swine virus (VESV)
  
  • Clinical sings ~ FMD
• San miguel sea lino virus (~VESV)
• Feline calicivirus
  
  • ​Respiratory disease, mucosal erosions
• Bovine-, cetacean-, primate-, reptile-, skunk caliciviruses​

Question 18

Caliciviridae

Lagovirus genus

Answer 18

• Etymology: Lagomorpha: rabbit, hare
• Rabbit hemorrhagic disease (RHD)
• European brown hare disease (EBHD)

Question 19

Caliciviridae

Norovirus genus

Answer 19

• Etymology: Norwalk
• Norwalk, Hawaii, Mexico, Southampton viruses
  • → human food-borne gastroenteritis

Question 20

Caliciviridae

Give the unassinged caliciviruses

Answer 20

Bovine-, canine-, porcine-, fowl-, mink caliciviruses

Question 21

Astroviridae

Answer 21

• Etymology: Astra: star
• Morphology:
  
  • ​Linear
  • +ssRNA genome
  • Icosahedral capsid
  • No envelope
• Resistance: good (pH resistance)
• Biological properties: ​Stenoxen – host specific, but some are zoonotic
• Antigenic properties: good antigens
• Diagnostics:
  
  • ​Isolation - on CPE
  • IF, AGID, PCR

Question 22

Astroviridae

List the different genera

Answer 22

• Avastrovirus genus
• Mamastrovirus genus

Question 23

Astroviridae

Avastrovirus genus

Answer 23

• Chicken nephritis
• Duck hepatitis (2)
• Turkey astrovirus (PEMS)

Question 24

Astroviridae

Masmastrovirus genus

Answer 24

Bovine -, ovine-, porcine- feline-, human gastroenteritis