Classification and nomenclature of viruses Flashcards
1
Q
The main criteria for the classification of viruses established by the International Commite on Taxonomy of viruses are:
A
- the type and character of the viral genome
- the strategy of viral replication
- the morphology of the virion
2
Q
Families end in
A
-viridae
3
Q
subfamily
A
- deals with the complex interrelationships among member viruses in a family
- ends in -virinae
4
Q
genera and species
A
- the classification of genera and species within a family are based on criteria which include: host species, pathogenesis, nucleic acid homology and antigenic difference.
- ends in virus
5
Q
parvoviridae
A
- very small
- replication occurs in actively dividing cells and takes place in the nucleus
- form acidiophilic intranuclear inclusion bodies
- remarkably resistant
6
Q
papillomaviridae
A
- causes warts( proteins promote cell growth)
- small
- genome may be episomal or integrated into host cell DNA
- replicate in the nucleus
- stable in the environment
7
Q
Adenoviruses
A
- medium sized
- possess filament/ fibers
- fiber contains viral attachment proteins
- replicate in host cell nucleus
- produce basophilic intranuclear inclusion bodies
- cause latent infections
8
Q
Asfarviridae
A
- large virons
- replication occurs in the cytoplasm of host cell and soft ticks
- -produce intracytoplasmic inclusion bodies
- African swine fever
9
Q
Herpersviridae
A
- creep
- consist of three subfamilies
- replicate in the nucleus
- acidophilic intranuclear inclusion bodies
- fragile
- cytomegaly or syncytia
- life long persistance
10
Q
Poxviridae
A
- largest of all the viruses that cause disease in domestic animals
- complex in structure
- replication occurs in the cell cytoplasm
- eosinophilic intracytoplasmic inclusion bodies
- all produce skin lesions
- can survive for months to years
11
Q
Hepadnaviridae
A
- liver
- partially double-stranded and partially single-stranded DNA
- replicates in the nucleus of hepatocytes
- replication involves reverse transcriptase
- acute or chronic hepatitis
12
Q
Circoviridae
A
- smallest known virus of vertebrates and plants
- single-stranded DNA
- only replicates in the nucleus of dividing cells
- stable in the environment
13
Q
Picornviridae
A
- stable
- no inclusion bodies
- rapidly cytolytic
- multiple serotypes may produce same disease syndrome, with very little or no cross-protection between serotypes
14
Q
Caliciviridae
A
-cup
-stable in the environment
-no inclusion bodies
-+ sense RNA
-replication takes place in cell cytoplasm
-
15
Q
Togaviridae
A
- fragile
- no inclusion bodies
- +sense RNA genome
- enveloped
- replication in the cytoplasm
- infection of host cells is acute and cytolytic
16
Q
arteriviridae
A
- fragile
- (+) sense RNA/ ennveloped
- replication in the cytoplasm
- primary host cells are macrophages
- persistent infection
17
Q
Flaviviridae
A
- yellow
- enveloped/ (+) sense RNA
- replication occurs in the cytoplasm
- infection of vertebrate cells is cytolytic
18
Q
Reoviridae
A
- respiratory enteric orphan
- two to three layered capsids
- segmented
- double-stranded RNA genome
- genetic reassortment
- replication in the cytoplasm
- acidophilic, intracytoplasmic, perinuclear inclusion bodies
- moderate to stable in the environment
19
Q
Birnaviridae
A
- two segments of RNA/ double stranded
- kill cells they multiply in
- stable in the environment
20
Q
Coronaviridae
A
- crown
- envelope with club-shaped surface
- replication occurs in the cytoplasm
- narrow host range and readily establish persistent infections
21
Q
Paramyxoviridae
A
- large virion
- pleomorphic envelope
- (-) sense RNA
- penetrate host cell by fusion with the plasma membrane
- all member produce intracytoplasmic inclusions, but some produce intranuclear bodies
- produce syncytia or multinucleated giant cells
- some cause persistent infections
22
Q
Orthomyxoviridae
A
- pleomorphic virions
- segmented genome
- (-) sense single stranded RNA
- genetic reassortment
- replication takes place in the nucleus and the cytoplasm
- labile in the environment
23
Q
Rhabdoviridae
A
- bullet
- single-stranded (-) sense RNA
- replication occurs in the cytoplasm
- Negri bodies
- inactivated by UV light
- rabies
24
Q
Retroviridae
A
- diploid genome
- (+) sense/ single stranded RNA
- reverse transcriptase
- provirus
- host remain chronically infected
- labile viruses
25
Q
Bunyaviridae
A
- genetic reassortment
- tripple segmented
- replication occurs in the cytoplasm
- labile in the environment
26
Q
Bornaviridae
A
- (-) sense/single-stranded genome
- intranuclear inclusion bodies
- particular affinity for nervous tissues
- labile virion
27
Q
Astroviridae
A
- star
- (+) sense ssRNA
- five to six pointed stars on surface
- replicate in the cytoplasm
- no inclusion bodies
- moderately stable
