Picornaviridae

Question 1

Morphology

Answer 1

+ssRNA genome
~25nm icosahedral capsid

non enveloped

Question 2

Resistance

Answer 2

generally good
Entero-, Hepato-, Tescho-: 56°C, pH 3
Cardio-, Rhinovirus: weaker

Question 3

Biological properties

Answer 3

Baltimore IV.: genome ~ mRNA – short replication cycle

single polyprotein processed by viral enzymes

generally stenoxen (except Aphtho) – in vitro too

CPE: rounding, rhexis

Question 4

Diagnosis

Answer 4

isolation
IF, CF (FMD)
indirect: VN, CF, AGID, ELISA
PCR

Question 5

Antigenetic properties

Answer 5

good antigens
serotypes – no cross protection
transcapsidation

Question 6

Genus

Answer 6

Enterovirus genus
Teschovirus genus
Hepatovirus genus
Tremovirus genus
Cardiovirus genus
Aphthovirus genus (FMD belongs here)
Erbovirus genus
Parechovirus genus
Kobuvirus genus
Avihepatovirus genus

Question 7

Enterovirus genus:

Answer 7

(enteron – intestine)

Swine vesicular disease (SVD, porcine picornavirus 9)
•swine – clinical signs ~ FMD
•antigenic structure ~ coxsackie 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 cytopathic human orphan

Rhinoviruses (rhinos – nose)
•Common cold – cattle (1-3), human (~100)
•thermosensitive mutants - rhinitis

Simian enteroviruses

Question 8

Teschovirus genus:

Answer 8

(Teschen) – formerly Entero

Porcine teschovirus 1: Teschen/Talfan disease
•poliomyelitis, paralysis

Porcine teschovirus 2-8, 10-13: apathogen

Question 9

Hepatovirus genus:

Answer 9

(hepato - liver)
Hepatitis A
•human – hepatitis, icterus
Simian hepatitis A

Question 10

Tremovirus genus

Answer 10

(tremor)

Avian encephalomyelitis – chicken, Epidemic tremor

Question 11

Cardiovirus genus

Answer 11

(cardia - heart)

Encephalomyocarditis virus
•euryxen
•reservoir: rodents
•swine, horse, human, elephants

Question 12

Aphthovirus genus

Answer 12

(aphtha – vesicles)

Foot and mouth disease (FMD):
•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 13

Erbovirus genus:

Answer 13

(equine rhinitis B)

Equine rhinitis B