The ''Caliciviridae'' are a family of "small round structured"
viruses
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsky's ...
, members of Class IV of the
Baltimore scheme. Caliciviridae bear resemblance to enlarged picornavirus and was formerly a separate genus within the picornaviridae. They are
positive-sense
In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the conte ...
, single-stranded
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
which is not segmented. Thirteen species are placed in this family, divided among eleven genera.
Diseases associated with this family include feline calicivirus (respiratory disease), rabbit hemorrhagic disease virus (often fatal hepatitis), and Norwalk group of viruses (gastroenteritis).
Caliciviruses naturally infect vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, wi ...
s, and have been found in a number of organisms such as humans
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
, cattle
Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Adult females are referred to as cows and adult ...
, pig
The pig (''Sus domesticus''), often called swine, hog, or domestic pig when distinguishing from other members of the genus '' Sus'', is an omnivorous, domesticated, even-toed, hoofed mammal. It is variously considered a subspecies of ''Sus ...
s, cats
The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...
, chicken
The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adu ...
s, reptile
Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates ( lizards and snakes) and rhynchoce ...
s, dolphin
A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae ( ...
s and amphibian
Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arbor ...
s. The caliciviruses have a simple construction and are not enveloped. The capsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or m ...
appears hexagonal
In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°.
Regular hexagon
A '' regular hexagon'' ha ...
/spherical
A sphere () is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. A sphere is the set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the ...
and has icosahedral
In geometry, an icosahedron ( or ) is a polyhedron with 20 faces. The name comes and . The plural can be either "icosahedra" () or "icosahedrons".
There are infinitely many non- similar shapes of icosahedra, some of them being more symmetric ...
symmetry (T=1 or T=3) with a diameter of 35–39 nm.
Caliciviruses are not very well studied because until recently, they could not be grown in culture
Culture () is an umbrella term which encompasses the social behavior, institutions, and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups.Ty ...
, and they have a very narrow host range and no suitable animal model. However, the recent application of modern genomic technologies has led to an increased understanding of the virus family. A recent isolate from rhesus monkey
The rhesus macaque (''Macaca mulatta''), colloquially rhesus monkey, is a species of Old World monkey. There are between six and nine recognised subspecies that are split between two groups, the Chinese-derived and the Indian-derived. Generally b ...
s— Tulane virus—can be grown in culture, and this system promises to increase understanding of these viruses.[Yu G, Zhang D, Guo F, Tan M, Jiang X, Jiang W (2013). "Cryo-EM structure of a novel calicivirus, Tulane Virus". ''PLoS One'' 8(3):e59817. ]
Etymology
Calici- comes from the Latin word ''Calyx'' and the Greek word ''kalyx''. The words mean a cup or chalice, a Calix. This comes from the strains having visible cup-shaped depressions.
Taxonomy
The following genera are recognized:
* '' Bavovirus''
* '' Lagovirus''
* '' Minovirus''
* '' Nacovirus''
* '' Nebovirus''
* ''Norovirus
Norovirus, sometimes referred to as the winter vomiting disease, is the most common cause of gastroenteritis. Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain. Fever or headaches may also occur. Symptoms usually de ...
''
* '' Recovirus''
* '' Salovirus''
* '' Sapovirus''
* '' Valovirus''
* '' Vesivirus''
A number of other caliciviruses remain unclassified, including the chicken calicivirus.
Virology
All viruses in this family possess a nonsegmented, polyadenylated, positive-sense, single-strand RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ...
around 7.5–8.5 kilobases in length, enclosed in an icosahedral capsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or m ...
of 27–40 nanometer
330px, Different lengths as in respect to the molecular scale.
The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American and British English spelling differences#-re ...
s in diameter.
Life cycle
Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment to host receptors, which mediate endocytosis. Replication follows the positive-stranded RNA virus replication model. Positive-stranded RNA virus transcription is the method of transcription. Translation takes place by leaky scanning, and RNA termination-reinitiation. Vertebrates serve as the natural host. Transmission routes are fecal-oral.
Human disease
Calicivirus infections commonly cause moderate to severe gastroenteritis
Gastroenteritis, also known as infectious diarrhea and gastro, is an inflammation of the gastrointestinal tract including the stomach and intestine. Symptoms may include diarrhea, vomiting, and abdominal pain. Fever, lack of energy, and dehydrat ...
, which is the inflammation
Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molec ...
of the stomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomac ...
and intestine
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans a ...
s (e.g. the Norwalk virus
Norovirus, sometimes referred to as the winter vomiting disease, is the most common cause of gastroenteritis. Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain. Fever or headaches may also occur. Symptoms usually devel ...
). Symptoms can include vomiting
Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose.
Vomiting can be the result of ailments like food poisoning, gastroenterit ...
and diarrhea
Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...
. These symptoms emerge after an incubation time of 2 days and the symptoms only generally last for 3 days. Most calicivirus infections do not require medical intervention, but those who are immunocompromised
Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors tha ...
may need to be hospitalized due to serious fluid loss.
History
Establishing the viral etiology took many decades due to the difficulty of growing the virus in cell culture. In the 1940s and 1950s in the United States and Japan, caliciviridae could not be grown in culture, but as an experiment bacterial free filtrate of diarrhea was given to volunteers to check if viruses were present in volunteers' stool. These experiments demonstrated that nonbacterial, filterable agents had the capability of causing enteric disease in humans. In 1968, an outbreak at a Norwalk elementary school (e.g. Norwalk virus
Norovirus, sometimes referred to as the winter vomiting disease, is the most common cause of gastroenteritis. Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain. Fever or headaches may also occur. Symptoms usually devel ...
) in Ohio led to stool samples again being given to volunteers and serially passaged to other people. Finally, in 1972, Kapikian and his colleagues isolated the Norwalk virus from volunteers using immune electron microscopy, a process that involves looking directly at antibody-antigen complexes. The classification of this one Norwalk virus strain served as the prototype for other species and small round structured viruses later known as Norovirus
Norovirus, sometimes referred to as the winter vomiting disease, is the most common cause of gastroenteritis. Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain. Fever or headaches may also occur. Symptoms usually de ...
.
Animal viruses
Feline calicivirus (FCV)—a member of the ''Vesivirus''—represents an important pathogen of cats.
'' Sapovirus'', ''Norovirus
Norovirus, sometimes referred to as the winter vomiting disease, is the most common cause of gastroenteritis. Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain. Fever or headaches may also occur. Symptoms usually de ...
'', and '' Vesivirus'' have been detected in pigs, making this animal species of particular interest in the study of calicivirus pathogenesis and host range.
The first mouse norovirus, murine norovirus 1 (MNV-1), was discovered in 2003. Since then, numerous murine norovirus strains have been identified and they were assigned a new genogroup in the genus ''Norovirus''.
Rabbit hemorrhagic disease virus is a pathogen of rabbits that causes major problems throughout the world where rabbits are reared for food and clothing, make a significant contribution to ecosystem ecology
Ecosystem ecology is the integrated study of living ( biotic) and non-living (abiotic) components of ecosystems and their interactions within an ecosystem framework. This science examines how ecosystems work and relates this to their components s ...
, and where they support valued wildlife as a food source.
Uses
Australia
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country b ...
and New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island country ...
, in an effort to control their rabbit populations, have intentionally spread rabbit calicivirus.
References
External links
ICTV Report: ''Caliciviridae''
description page from the International Committee on Taxonomy of Viruses
The International Committee on Taxonomy of Viruses (ICTV) authorizes and organizes the taxonomic classification of and the nomenclatures for viruses. The ICTV has developed a universal taxonomic scheme for viruses, and thus has the means to a ...
site
MicrobiologyBytes: Caliciviruses
Virus Pathogen Database and Analysis Resource (ViPR): Caliciviridae
3D macromolecular structures of Caliciviridae from the EM Data Bank(EMDB)
ICTV
{{Taxonbar, from=Q1026758
Riboviria
Virus families