Aichi virus: Difference between revisions

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==Reproductive Cycle in a Host Cell==
==Reproductive Cycle in a Host Cell==
Reproduction occurs when there is successful attachment of the virus to a host’s receptors. Host receptors help with endocytosis of the virus into the cell. The capsid of the of the virus changes and is thought to open a pore within the host's endosomal membrane and the viral genomic RNA infiltrates the host cell cytoplasm. A protein, VPg, is taken out from the viral RNA and translated into a processed polyprotein. Replication happens in "viral factories" from the membrane vesicles resulting from the ER. A double stranded RNA genome is made from the genomic ssRNA (+). The dsRNA genome is transcribed/replicated thereby providing vial mRNAs/new ssRNA (+) genomes. It is thought that new genomic RNA is put into assembled procapsids. The cell lyses and the viruses are released .
Reproduction occurs when there is successful attachment of the virus to a host’s receptors. Host receptors help with endocytosis of the virus into the cell. The capsid of the of the virus changes and is thought to open a pore within the host's endosomal membrane and the viral genomic RNA infiltrates the host cell cytoplasm. A protein, VPg, is taken out from the viral RNA and translated into a processed polyprotein. Replication happens in "viral factories" from the membrane vesicles resulting from the ER. A double stranded RNA genome is made from the genomic ssRNA (+). The dsRNA genome is transcribed/replicated thereby providing vial mRNAs/new ssRNA (+) genomes. It is thought that new genomic RNA is put into assembled procapsids. The cell lyses and the viruses are released .
The virus’s L protein is needed for viral RNA replication. There has been ongoing research about the significance of the L protein, which is important for viral RNA replication and excapsidation within virus replication. This is a unique aspect of the Aichi Virus compared to other Picornoviruses . [[File:gastroenteritis.jpg|thumb|500px] Gastroenteritis is an infection of the large and small bowels [http://www.mayoclinic.com/health/medical/IM04033 MayoClinic] ]]
The virus’s L protein is needed for viral RNA replication. There has been ongoing research about the significance of the L protein, which is important for viral RNA replication and excapsidation within virus replication. This is a unique aspect of the Aichi Virus compared to other Picornoviruses . [[File:gastroenteritis.jpg|thumb|500px Gastroenteritis is an infection of the large and small bowels [http://www.mayoclinic.com/health/medical/IM04033 MayoClinic] ]]


==Viral Ecology & Pathology==
==Viral Ecology & Pathology==

Revision as of 19:31, 3 May 2013

A Viral Biorealm page on the family Aichi virus


Phylogenetic Tree of the Kobuvirus Genus that includes the Aichi Virus Picornavidae

.

Baltimore Classification

The Aichi Virus is a (+) ssRNA [1].

Higher order categories

Viruses; ssRNA viruses; ssRNA positive-strand viruses, no DNA stage; Picornavirales; Picornaviridae; Kobuvirus; Aichi Virus [2]

Description and Significance

The Aichi Virus is a member of the Kobuvirus genus in the Picornaviridae family. It is a positive sense, single-stranded RNA virus [1]. The virus Aichi Virus appears to morphologically resemble astroviruses when examined by electron microscopy [3]. The virus was first isolated from an individual with a non-bacterial oyster associated gastroenteritis [4]. The virus is a known cause of gastroenteritis in humans. It is the only virus in the Kobuvirus genus that has been found in humans [5].

Non-eveloped and spherical shape of Aichi Virus Springer Images

Genome Structure

The Aichi Virus is a positive sense single stranded RNA virus with a genome of 8,280 nt and a poly (A) tail, which helps with the stability and decreases degradation of the RNA molecule [6]. It has a 59% G+C content, which is very high for Picornaviridae. It has a large opening reading frame at 7,302 nt, that translates for a potential polyprotein precursor of 2,433 amino acids [1]. The virus also can be divided into 2 genotypes, A and B, with around 90% sequence homology [1]. The stem-loop at the 5' end of the Aichi Virus genome has been found to be an element involved in both viral RNA replication and production of infectious virus particles [7].

Virion Structure

The structure of the virus is noted to be a spherical shape that resembles an astrovirus when looked at underneath an electron microscopy [3].

Reproductive Cycle in a Host Cell

Reproduction occurs when there is successful attachment of the virus to a host’s receptors. Host receptors help with endocytosis of the virus into the cell. The capsid of the of the virus changes and is thought to open a pore within the host's endosomal membrane and the viral genomic RNA infiltrates the host cell cytoplasm. A protein, VPg, is taken out from the viral RNA and translated into a processed polyprotein. Replication happens in "viral factories" from the membrane vesicles resulting from the ER. A double stranded RNA genome is made from the genomic ssRNA (+). The dsRNA genome is transcribed/replicated thereby providing vial mRNAs/new ssRNA (+) genomes. It is thought that new genomic RNA is put into assembled procapsids. The cell lyses and the viruses are released .

The virus’s L protein is needed for viral RNA replication. There has been ongoing research about the significance of the L protein, which is important for viral RNA replication and excapsidation within virus replication. This is a unique aspect of the Aichi Virus compared to other Picornoviruses .

500px Gastroenteritis is an infection of the large and small bowels MayoClinic

Viral Ecology & Pathology

Not much is known about the epidemiology of the virus. However, the Aichi Virus was first found in 1989 as the cause of oyster-associated non-bacterial gastroenteritis in man.It has also been isolated from Japanese travelers in Southeast Asia and has been found in fecal specimens of children with diarrhea in several countries like Brazil, France, Germany, and Tunisia. An infection caused by the Aichi virus can result in Gastroenteritis (the stomach flu). The virus is found to be mostly food borne. Symptoms include nausea and vomiting among others. Not much else is known about the virulence factors.

References

Example: J Bacteriol. 2005 May; 187(9): 3188–3200. doi: 10.1128/JB.187.9.3188-3200.2005


Aichi Virus human/hun298/2000/hun. (n.d.). Retrieved from http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=571505&lvl=3&lin=f&keep=1&srchmode=1&unlock

Sasaki, J. (2001). Construction of an infectious cdna clone of Aichi Virus (a new member of the family picornaviridae) and mutational analysis of a stem-loop structure at the 5' end of the genome. J Virol,75(17), 8021-30. , doi: 10.1128/JVI.75.17.8021-8030.2001

Viralzone:kobuvirus. (n.d.). Retrieved from: http://viralzone.expasy.org/viralzone/all_by_species/652.html

Yang S, Zhang W, Shen Q, Yang Z, Zhu J, Cui L, et al. Aichi Virus strains in children with gastroenteritis, China [letter]. Emerg Infect Dis [serial on the Internet]. 2009 Oct [12 Feb 2013]. doi: 10.3201/eid1510.090522

Yamashita, T. (1998). Complete nucleotide sequence and genetic organization of Aichi Virus, a distinct member of the picornaviridae associated with acute gastroenteritis in humans. JVirol, 72(10), doi: http://jvi.asm.org/