Erbovirus
| Erbovirus | |
|---|---|
| Virus classification | |
| Group: | Group IV ((+)ssRNA) |
| Order: | Picornavirales |
| Family: | Picornaviridae |
| Genus: | Erbovirus |
| Type Species | |
|
|
Erbovirus is a genus of viruses in the order Picornavirales, in the family Picornaviridae. Horses serve as natural hosts. There is currently only one species in this genus: the type species Erbovirus A. Diseases associated with this genus include: upper respiratory tract disease with viremia and fecal shedding. Viruses belonging to the Erbovirus genus have been isolated in horses with acute upper febrile respiratory disease. The structure of the erbovirus virion is icosahedral, having a diameter of 27-30 nm.
Group: ssRNA(+)
Viruses in Erbovirus are non-enveloped, with icosahedral, spherical, and round geometries, and T=pseudo3 symmetry. The diameter is around 30 nm. Genomes are linear and non-segmented, around 8.8kb in length.
The virion essentially is a nucleocapsid that is visible under an electron microscope and is able to infect cultured cells from a broad range of mammals including rabbit kidney (RK13), African green monkey kidney (Vero), equine foetal kidney (EFK), and is able to infect humans.
The RNA genome of the virion is inside the capsid that is composed by twelve capsomers, which are cup-shaped pentamers.
The erbovirus particles are non-enveloped and the molecular mass of the virions is around 8-9 x 106 Daltons. They are resistant to inactivation by non-ionic detergent treatment.
Erbovirus, as a typical picornavirus, has a single-stranded positive-sense RNA genome. A feature of the picornavirus genome is the virus protein that is linked at the 5’ end of the genome, known as "VPg" (Virus-Protein-attached-to-the-Genome). In addition, the 3’ end of the genome has a poly-A tail. The transcription of the erbovirus genome gives rise to a polyprotein which is further more processed and cleaved to give the mature viral proteins, in order from 5' to 3' : L ("Leader"), VP4, VP2, VP3, VP1, 2A, 2B, 2C, 3A (Vpg), 3B, 3Cpro, 3Dpol.
The type (and only) species of the Erbovirus genus is Equine rhinitis B virus which was recently found to have three phylogenetically distinct serotypes, equine rhinitis B virus (ERBV)-1, ERBV-2 and ERBV-3. One such phylogenetic group was found to comprise mostly "acid stable" virus isolates, surviving pH 3.6 for 1 hour at room temperature.
Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the virus to host receptors, which mediates endocytosis. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method of transcription. Translation takes place by ribosomal skipping. The virus exits the host cell by lysis, and viroporins. Horses serve as the natural host.
...
Wikipedia