|
Calicivirus
The ''Caliciviridae'' are a family of "small round structured" viruses, 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, single-stranded RNA 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 vertebrates, and have been found in a number of organisms such as humans, cattle, pigs, cats, chickens, reptiles, dolphins and amphibians. The caliciviruses have a simple construction and are not enveloped. The capsid appears hexagonal/spherical and has icosahedral symmetry (T=1 or T=3) with a diameter of 35–39 nm. Caliciviruses are not very well studied because until recently, they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feline Calicivirus
''Feline calicivirus'' (FCV) is a virus of the family ''Caliciviridae'' that causes disease in cats. It is one of the two important viral causes of respiratory infection in cats, the other being '' Felid alphaherpesvirus 1''. FCV can be isolated from about 50% of cats with upper respiratory infections. Cheetahs are the other species of the family Felidae known to become infected naturally. Viral structure and pathogenesis Different strains of FCV can vary in virulence (the degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host). Being an RNA virus, FCV has a high elasticity of its genome, which makes it more adaptable to environmental pressures. This not only makes the development of vaccines more difficult, but also allows for the development of more virulent strains. In persistently infected cats, the gene for the major structural protein of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vesivirus
''Vesivirus'' is a genus of viruses, in the family '' Caliciviridae''. Swine, sea mammals, and felines serve as natural hosts. There are two species in this genus. Diseases associated with this genus include: respiratory disease, ''Feline calicivirus'' (FCV); conjunctivitis, and respiratory disease. Taxonomy The genus contains the following two species: *''Feline calicivirus'' *'' Vesicular exanthema of swine virus'' Other, unofficial Vesi-like viruses include canine calicivirus, San Miguel sealion virus, vesivirus Cro1 and walrus calicivirus. Virion properties Morphology Virions consist of a capsid. Virus capsid is non-enveloped, and are round with icosahedral symmetry and triangulation number T=3. The isometric capsid has a diameter of 35–39 nm. Empty virions have diameter of 23 nm, with triangulation number T=1. The capsid surface structure reveals a regular pattern with distinctive features, including 32 cup-shaped depressions. The capsomer arrangement is clea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sapovirus
Sapovirus is a genetically diverse genus of single-stranded positive-sense RNA, non-enveloped viruses within the family ''Caliciviridae''. Together with norovirus, sapoviruses are the most common cause of acute gastroenteritis (commonly called the "stomach flu" although it is not related to influenza) in humans and animals. It is a monotypic taxon containing only one species, the ''Sapporo virus''. Natural hosts for the virus are humans and swine. The virus is transmitted through oral/fecal contact. Sapovirus commonly occurs in children and infants and therefore is often spread in nurseries and daycares; however, it has also been found in long-term care facilities. This could be due to a lack of personal hygiene and sanitation measures. Common symptoms include diarrhea and vomiting. The sapovirus was initially discovered in an outbreak of gastroenteritis in an orphanage in Sapporo, Japan, in 1977. Transmission route and host susceptibility Sapovirus is spread via the fecal/ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Envelope
A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes. Numerous human pathogenic viruses in circulation are encased in lipid bilayers, and they infect their target cells by causing the viral envelope and cell membrane to fuse. Although there are effective vaccines against some of these viruses, there is no preventative or curative medicine for the majority of them. In most cases, the known vaccines operate by inducing antibodies that prevent the pathogen from entering cells. This happens in the case of enveloped viruses when the antibodies bind to the viral envelope proteins. The membrane fusion event that triggers viral entrance is caused by the viral fusion protein. Many enveloped viruses only have one protein visible on the surface of the particle, which is required for both mediating adhesion to the cell surface and for the subsequent membrane fusi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898,Dimmock p. 4 more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles, or ''virions'', consisting of (i) the genetic material, i.e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 brown or grey in colour, it is in length with a tail and weighs . It is native to South, Central, and Southeast Asia and has the widest geographic range of all non-human primates, occupying a great diversity of altitudes and a great variety of habitats, from grasslands to arid and forested areas, but also close to human settlements. Feral colonies are found in the United States, thought to be either released by humans or escapees after hurricanes destroyed zoo and wildlife park facilities. The rhesus macaque is diurnal, arboreal, and terrestrial. It is mostly herbivorous, mainly eating fruit, but will also consume seeds, roots, buds, bark, and cereals. Studies show almost 100 different plant species in its diet. Rhesus macaques are gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 develop 12 to 48 hours after being exposed, and recovery typically occurs within one to three days. Complications are uncommon, but may include dehydration, especially in the young, the old, and those with other health problems. The virus is usually spread by the fecal–oral route. This may be through contaminated food or water or person-to-person contact. It may also spread via contaminated surfaces or through air from the vomit of an infected person. Risk factors include unsanitary food preparation and sharing close quarters. Diagnosis is generally based on symptoms. Confirmatory testing is not usually available but may be performed by public health agencies during outbreaks. Prevention involves proper hand washing and disinfection of con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nebovirus
''Nebovirus'' is a genus of 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 ..., in the family '' Caliciviridae''. Bovine serve as natural hosts. There is only one species in this genus: ''Newbury 1 virus''. Diseases associated with this genus include: Gastroenteritis. Structure Viruses in ''Nebovirus'' are non-enveloped, with icosahedral geometries, and T=3, T=1 symmetry. The diameter is around 35 nm. Genomes are linear and non-segmented, around 8.3kb in length. Life cycle Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment 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 pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
