Enterovirus E | |
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Bovine enterovirus | |
Virus classification ![]() | |
(unranked): | Virus |
Realm: | Riboviria |
Kingdom: | Orthornavirae |
Phylum: | Pisuviricota |
Class: | Pisoniviricetes |
Order: | Picornavirales |
Family: | Picornaviridae |
Genus: | Enterovirus |
Species: | Enterovirus E |
Enterovirus E (formerly bovine enterovirus (BEV) [1] ) is a picornavirus of the genus Enterovirus . The virus may also be referred to as enteric cytopathic bovine orphan virus (ECBO). It is endemic in cattle populations worldwide, and although normally fairly nonpathogenic, it can cause reproductive, respiratory, or enteric disease – particularly when the animal is concurrently infected with another pathogen.
The virus is spread horizontally by either the oral-fecal route or by the respiratory route. Viral shedding may occur for several months after initial infection. The virus has not been shown to transmit from animals to humans.
In common with other picornaviruses, the capsid of BEV is composed of 60 copies of each of four structural proteins, VP1, VP2, VP3 and VP4, in icosahedral symmetry, [2] at about 27 nm in diameter, and enclosing a single stranded positive sense RNA genome of about 7,500 bases. The capsid is not enveloped and roughly spherical with an outer radius of 159 Ångströms and an inner radius of 107 Å. The outer surface of BEV is smoother than the closely related poliovirus due to the truncation of surface protein loops in BEV. [3] It is also smoother than the related human rhinovirus due to the extension of a surface loop in BEV. The three antigenic sites of BEV all occur on a surface ridge at the junction between VP1, VP2, and VP3. BEV has a crater-like depression at the icosahedral 5-fold axis [2] which descends into a cylindrical hole of 10 Å in diameter which runs almost to the inner surface of the capsid. A hydrophobic pocket contained within VP1 contains a myristic acid molecule, the removal of which appears to be a prerequisite for virus uncoating. [3] [4]
To replicate, BEV must attach to the host cell surface receptor, penetrate into the cell cytoplasm, and the genome must be uncoated. The host cell surface receptor for BEV has yet to be identified, but is sensitive to neuraminidase. [5]
BEVs were originally classified into seven serotypes, but are now accepted as falling into two serotypes, 1 and 2, which are further classified into subtypes. [6] BEV strain VG-5-27 of serotype 1, subtype 1, is the most extensively studied. The tissue tropism of serotype 1 is extremely broad, including human, sheep, horse, dog, camel, and other mammalian hosts. BEV-like sequences have even been reported in shellfish from water contaminated with bovine faeces. Serotype 2 viruses are only found in domestic cattle.
Most cattle show no clinical signs when infected with the virus. However abortion, stillbirth, infertility, and neonatal mortality can occur following infection of the reproductive tract. Enteric signs include diarrhea and weight loss, and respiratory infection can produce a mucoid nasal discharge.
As clinical signs are fairly nonspecific and bovine enterovirus is ubiquitous in cattle populations, other causes of disease must be ruled out before diagnosing enterovirus as the cause of disease. Electron microscopy, PCR, complement fixation, antibody fluorescence, [7] [8] neutralization test, [8] and haemagglutination can be used to identify the virus in tissues or secretions.
Treatment is symptomatic. Appropriate isolation and hygiene measures should be employed to minimise the spread of disease during an outbreak.
The virus has been investigated for its antitumor capabilities, as it is capable of replicating within breast cancer cell lines and producing a cytopathic effect in human monocytes. [9]
Bluetongue disease is a noncontagious, insect-borne, viral disease of ruminants, mainly sheep and less frequently cattle, yaks, goats, buffalo, deer, dromedaries, and antelope. It is caused by Bluetongue virus (BTV). The virus is transmitted by the midges Culicoides imicola, Culicoides variipennis, and other culicoids.
The rhinovirus is the most common viral infectious agent in humans and is the predominant cause of the common cold. Rhinovirus infection proliferates in temperatures of 33–35 °C (91–95 °F), the temperatures found in the nose. Rhinoviruses belong to the genus Enterovirus in the family Picornaviridae.
Coxsackie B4 virus are enteroviruses that belong to the Picornaviridae family. These viruses can be found worldwide. They are positive-sense, single-stranded, non-enveloped RNA viruses with icosahedral geometry. Coxsackieviruses have two groups, A and B, each associated with different diseases. Coxsackievirus group A is known for causing hand-foot-and-mouth diseases while Group B, which contains six serotypes, can cause a varying range of symptoms like gastrointestinal distress myocarditis. Coxsackievirus B4 has a cell tropism for natural killer cells and pancreatic islet cells. Infection can lead to beta cell apoptosis which increases the risk of insulitis.
Coxsackie B is a group of six serotypes of coxsackievirus (CVB1-CVB6), a pathogenic enterovirus, that trigger illness ranging from gastrointestinal distress to full-fledged pericarditis and myocarditis.
A poliovirus, the causative agent of polio, is a serotype of the species Enterovirus C, in the family of Picornaviridae. There are three poliovirus serotypes: types 1, 2, and 3.
Picornaviruses are a group of related nonenveloped RNA viruses which infect vertebrates including fish, mammals, and birds. They are viruses that represent a large family of small, positive-sense, single-stranded RNA viruses with a 30 nm icosahedral capsid. The viruses in this family can cause a range of diseases including the common cold, poliomyelitis, meningitis, hepatitis, and paralysis.
Foot-and-mouth disease virus (FMDV) is the pathogen that causes foot-and-mouth disease. It is a picornavirus, the prototypical member of the genus Aphthovirus. The disease, which causes vesicles (blisters) in the mouth and feet of cattle, pigs, sheep, goats, and other cloven-hoofed animals is highly infectious and a major plague of animal farming.
Enterovirus is a genus of positive-sense single-stranded RNA viruses associated with several human and mammalian diseases. Enteroviruses are named by their transmission-route through the intestine.
Adeno-associated viruses (AAV) are small viruses that infect humans and some other primate species. They belong to the genus Dependoparvovirus, which in turn belongs to the family Parvoviridae. They are small replication-defective, nonenveloped viruses and have linear single-stranded DNA (ssDNA) genome of approximately 4.8 kilobases (kb).
Orbivirus is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Sedoreovirinae. Unlike other reoviruses, orbiviruses are arboviruses. They can infect and replicate within a wide range of arthropod and vertebrate hosts. Orbiviruses are named after their characteristic doughnut-shaped capsomers.
Aphthovirus is a viral genus of the family Picornaviridae. Aphthoviruses infect split-hooved animals, and include the causative agent of foot-and-mouth disease, Foot-and-mouth disease virus (FMDV). There are seven FMDV serotypes: A, O, C, SAT 1, SAT 2, SAT 3 and Asia 1, and four non-FMDV serotypes belonging to three additional species Bovine rhinitis A virus (BRAV), Bovine rhinitis B virus (BRBV) and Equine rhinitis A virus (ERAV).
Astroviruses are a type of virus that was first discovered in 1975 using electron microscopes following an outbreak of diarrhea in humans. In addition to humans, astroviruses have now been isolated from numerous mammalian animal species and from avian species such as ducks, chickens, and turkey poults. Astroviruses are 28–35 nm diameter, icosahedral viruses that have a characteristic five- or six-pointed star-like surface structure when viewed by electron microscopy. Along with the Picornaviridae and the Caliciviridae, the Astroviridae comprise a third family of nonenveloped viruses whose genome is composed of plus-sense, single-stranded RNA. Astrovirus has a non-segmented, single stranded, positive sense RNA genome within a non-enveloped icosahedral capsid. Human astroviruses have been shown in numerous studies to be an important cause of gastroenteritis in young children worldwide. In animals, Astroviruses also cause infection of the gastrointestinal tract but may also result in encephalitis, hepatitis (avian) and nephritis (avian).
Kobuvirus is a genus of viruses in the order Picornavirales, in the family Picornaviridae. Humans and cattle serve as natural hosts. There are six species in this genus. Diseases associated with this genus include: gastroenteritis. The genus was named because of the virus particles' lumpy appearance by electron microscopy; "kobu" means "knob" in Japanese.
Erbovirus is a genus of viruses in the order Picornavirales, in the family Picornaviridae. Horses serve as natural hosts. There is only one species in this genus: Erbovirus A. Diseases associated with this genus include: upper respiratory tract disease with viremia and fecal shedding. Viruses belonging to the genus Erbovirus 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.
Vincent R. Racaniello is a Higgins Professor in the Department of Microbiology and Immunology at Columbia University's College of Physicians and Surgeons. He is a co-author of a textbook on virology, Principles of Virology.
Torovirus is a genus of enveloped, positive-strand RNA viruses in the order Nidovirales and family Tobaniviridae. They primarily infect vertebrates, especially cattle, pigs, and horses. Diseases associated with this genus include gastroenteritis, which commonly presents in mammals. Torovirus is the only genus in the monotypic subfamily Torovirinae. Torovirus is also a monotypic taxon, containing only one subgenus, Renitovirus.
Picornain 3C is a protease found in picornaviruses, which cleaves peptide bonds of non-terminal sequences. Picornain 3C’s endopeptidase activity is primarily responsible for the catalytic process of selectively cleaving Gln-Gly bonds in the polyprotein of poliovirus and with substitution of Glu for Gln, and Ser or Thr for Gly in other picornaviruses. Picornain 3C are cysteine proteases related by amino acid sequence to trypsin-like serine proteases. Picornain 3C is encoded by enteroviruses, rhinoviruses, aphtoviruses and cardioviruses. These genera of picoviruses cause a wide range of infections in humans and mammals.
Epizootic hemorrhagic disease virus, often abbreviated to EHDV, is a species of the genus Orbivirus, a member of the family Reoviridae. It is the causative agent of epizootic hemorrhagic disease, an acute, infectious, and often fatal disease of wild ruminants. In North America, the most severely affected ruminant is the white-tailed deer, although it may also infect mule deer, black-tailed deer, elk, bighorn sheep, and pronghorn antelope. It is often mistakenly referred to as “bluetongue virus” (BTV), another Orbivirus that like EHDV causes the host to develop a characteristic blue tongue due to systemic hemorrhaging and lack of oxygen in the blood. Despite showing clinical similarities, these two viruses are genetically distinct.
Triatoma virus (TrV) is a virus belonging to the insect virus family Dicistroviridae. Within this family, there are currently 3 genera and 15 species of virus. Triatoma virus belongs to the genus Cripavirus. It is non-enveloped and its genetic material is positive-sense, single-stranded RNA. The natural hosts of triatoma virus are invertebrates. TrV is a known pathogen to Triatoma infestans, the major vector of Chagas disease in Argentina which makes triatoma virus a major candidate for biological vector control as opposed to chemical insecticides. Triatoma virus was first discovered in 1984 when a survey of pathogens of triatomes was conducted in the hopes of finding potential biological control methods for T. infestans.
Astroviridae is a family of non-enveloped ssRNA viruses that cause infections in different animals. The family name is derived from the Greek word astron ("star") referring to the star-like appearance of spikes projecting from the surface of these small unenveloped viruses. Astroviruses were initially identified in humans but have since been isolated from other mammals and birds. This family of viruses consists of two genera, Avastrovirus (AAstV) and Mamastrovirus (MAstV). Astroviruses most frequently cause infection of the gastrointestinal tract but in some animals they may result in encephalitis, hepatitis (avian) and nephritis (avian).