Cardiovirus

{{Short description|Genus of viruses}} {{Use dmy dates|date=April 2017}} {{virusbox | image = Journal.pone.0142415.g001.B.png | image_caption = TEM micrograph of Encephalomyocarditis virus virions <br> bar scale equals 100 nm | taxon = Cardiovirus }}

'''Cardiovirus''' are a group of viruses within order ''Picornavirales'', family ''Picornaviridae''. Vertebrates serve as natural hosts for these viruses.<ref name=":1">{{Cite journal|last1=Blinkova|first1=Olga|last2=Kapoor|first2=Amit|last3=Victoria|first3=Joseph|last4=Jones|first4=Morris|last5=Wolfe|first5=Nathan|last6=Naeem|first6=Asif|last7=Shaukat|first7=Shahzad|last8=Sharif|first8=Salmaan|last9=Alam|first9=Muhammad Masroor|last10=Angez|first10=Mehar|last11=Zaidi|first11=Sohail|date=2009-05-01|title=Cardioviruses Are Genetically Diverse and Cause Common Enteric Infections in South Asian Children|journal=Journal of Virology|language=en|volume=83|issue=9|pages=4631–4641|doi=10.1128/JVI.02085-08|issn=0022-538X|pmid=19193786|pmc=2668475}}</ref>

==Taxonomy== The genus contains the following species:<ref>{{cite web |title=Species List: ''Picornaviridae'' |url=https://ictv.global/report/chapter/picornaviridae/taxonomy/picornaviridae |publisher=International Committee on Taxonomy of Viruses |access-date=23 April 2025}}</ref>

* ''Cardiovirus dhusarah'' (Cardiovirus F) * ''Cardiovirus ranori'' (Cardiovirus C) * ''Cardiovirus rudhira'' (Cardiovirus E) * ''Cardiovirus rueckerti'' (Cardiovirus A), Encephalomyocarditis virus * ''Cardiovirus saffoldi'' (Cardiovirus D), Saffold virus * ''Cardiovirus theileri'' (Cardiovirus B), which contains Theiler's murine encephalomyelitis virus

==Structure== Cardioviruses are single-stranded RNA, non-enveloped viruses with icosahedral or spherical geometries, and a T=pseudo3 icosahedral capsid protein geometry. The diameter is around 30 nm. Genomes are linear and non-segmented, around 7.8 kb in length.<ref name="ViralZone" /><ref name=":2">{{Cite journal|last1=Himeda|first1=Toshiki|last2=Ohara|first2=Yoshiro|date=February 2012|title=Saffold Virus, a Novel Human Cardiovirus with Unknown Pathogenicity|journal=Journal of Virology|volume=86|issue=3|pages=1292–1296|doi=10.1128/JVI.06087-11|issn=0022-538X|pmc=3264344|pmid=22114344}}</ref> The T=pseudo3 icosahedral capsid of Cadiovirus is made of 60 protomers, each of which contains 4 polypeptides: VP1, VP2, VP3, and VP4.<ref>{{Cite web|title=Cardiovirus ~ ViralZone page|url=https://viralzone.expasy.org/99?outline=all_by_species|website=viralzone.expasy.org|access-date=2020-05-01}}</ref><ref name=":3">{{Cite journal|last1=Mullapudi|first1=Edukondalu|last2=Nováček|first2=Jiří|last3=Pálková|first3=Lenka|last4=Kulich|first4=Pavel|last5=Lindberg|first5=A. Michael|last6=van Kuppeveld|first6=Frank J. M.|last7=Plevka|first7=Pavel|date=2016-08-12|title=Structure and Genome Release Mechanism of the Human Cardiovirus Saffold Virus 3|journal=Journal of Virology|volume=90|issue=17|pages=7628–7639|doi=10.1128/JVI.00746-16|issn=0022-538X|pmc=4988150|pmid=27279624}}</ref> Inside the capsid of the virus there is a single linear, positive single-stranded RNA. On both the 3' and 5' ends of the genome there are untranslated regions.<ref name=":3" /> These untranslated regions of genome are important for the DNA replication, with the untranslated region on the 5' side being the location of internal ribosomal entry site (IRES).<ref name=":3" />

{| class="wikitable sortable" style="text-align:center" |- ! Genus !! Structure || Symmetry !! Capsid !! Genomic arrangement !! Genomic segmentation |- |''Cardiovirus''||Icosahedral||Pseudo T=3||Non-enveloped||Linear||Monopartite |}

==Life cycle== 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 −1 ribosomal frameshifting, viral initiation, and ribosomal skipping. The virus exits the host cell by lysis, and viroporins. Human and vertebrates serve as the natural host. Transmission routes are zoonosis and fomite.<ref name=ViralZone />

The 3’ end of the genome encodes a polyA tail while the 5’ end encodes a genome-linked protein. A unique feature of this genus is the presence of the L* protein, 18kDa, that is made out of frame from the polyprotein and is present in the DA subgroup of TMEV.<ref name=":4">{{Cite journal|last1=Tan|first1=Shawn Zheng Kai|last2=Tan|first2=Mark Zheng Yi|last3=Prabakaran|first3=Mookkan|date=January 2017|title=Saffold virus, an emerging human cardiovirus|journal=Reviews in Medical Virology|volume=27|issue=1|article-number=e1908|doi=10.1002/rmv.1908|issn=1052-9276|pmc=7169152|pmid=27723176}}</ref>

In the case of Encephalomyocarditis virus, the virus can cause encephalitis and myocarditis, mostly in rodents, which are natural hosts. The virus is transmitted from rodents to other animals. Severe epidemics have been seen in swine and elephants.<ref name=Fenner>{{cite book|author1=Fenner FJ |author2=Gibbs EPJ |author3=Murphy FA |author4=Rott R |author5=Studdert MJ |author6=White, DO |title=Veterinary Virology (2nd ed.)|publisher=Academic Press, Inc|year=1993|isbn=0-12-253056-X}}</ref>

{| class="wikitable sortable" style="text-align:center" |- ! Genus !! Host details !! Tissue tropism !! Entry details !! Release details !! Replication site !! Assembly site !! Transmission |- |''Cardiovirus''||Humans; vertebrates||Gastrointestinal tract; CNS; heart||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Zoonosis; fomite |}

==Clinical== Human cardioviruses were first isolated in 1981. Seven additional isolates have since been described in North America, Europe and South Asia. They have been associated with gastroenteritis, influenza-like symptoms and non-polio-associated acute flaccid paralysis. The first infection of cardiovirus in humans was identified in 2007 in a stool sample of an infant that was experiencing fever of unknown origin.<ref name=":2" /> It was subsequently named the Saffold virus after the lead researcher, Morris Saffold Jones.<ref name=":2" />

Other pathogenic cardioviruses isolated from humans include the Syr-Darya valley fever virus and Vilyuisk human encephalomyelitis virus.<ref>Anonymous. (2014) Genetic characterization of the Syr-Darya valley fever virus (SDVFV) (Picornaviridae, Cardiovirus) isolated from the blood of the patients and ticks ''Hyalomma as. asiaticum'' (Hyalomminae), ''Dermacentor daghestanicus'' (Rhipicephalinae) (Ixodidae) and ''Ornithodoros coniceps'' (Argasidae) in Kazakhstan and Turkmenistan. Vopr Virusol 59(4):15–19</ref> Diseases associated with cardioviruses include: myocarditis, encephalitis, multiple sclerosis, and type 1 diabetes.<ref name=":1" /><ref name=ViralZone>{{cite web|title=Viral Zone|url=http://viralzone.expasy.org/all_by_species/99.html|publisher=ExPASy|accessdate=15 June 2015}}</ref><ref name=ICTV>{{cite web |title=Virus Taxonomy: 2020 Release |url=https://ictv.global/taxonomy |publisher=International Committee on Taxonomy of Viruses (ICTV) |date=March 2021 |access-date=20 May 2021}}</ref>

==References== {{Reflist|2}}

==External links== * [http://viralzone.expasy.org/all_by_species/99.html '''Viralzone''': Cardiovirus] * [http://ictvonline.org/virusTaxonomy.asp '''ICTV'''] {{Baltimore classification}}

Category:Virus genera Category:Cardioviruses