Coronavirus Gammacoronavirus is a genus of animal virus belonging to the коронавирус в сингапуре информация family Coronaviridae. Coronaviruses are enveloped viruses with a positive-sense single-stranded RNA genome коронавирус в сингапуре информация and a helical symmetry.
The genomic size of coronaviruses ranges from approximately коронавирус в сингапуре информация 27 to 32 kilobases, which is the longest size for any known RNA virus. Coronaviruses primarily infect the upper respiratory or gastrointestinal tract of mammals and birds. Five to six different currently known strains of coronaviruses infect humans.
The most publicized human coronavirus, SARS-CoV which causes severe acute respiratory syndrome (SARS), has a unique pathogenesis because it causes both upper and коронавирус в сингапуре информация lower respiratory tract infections and can also cause gastroenteritis. Middle East respiratory коронавирус в сингапуре информация syndrome coronavirus (MERS-CoV) also causes a lower respiratory tract infection in humans. Coronaviruses коронавирус в сингапуре информация are believed to cause a significant percentage of all common colds in human adults. Coronaviruses also cause a range of diseases in livestock animals and domesticated pets, some of which can be serious and are a коронавирус в сингапуре информация коронавирус в сингапуре информация threat to the farming industry. Economically significant coronaviruses of livestock animals include коронавирус в сингапуре информация infectious bronchitis virus (IBV) which mainly causes respiratory disease in chickens and seriously affects the poultry industry worldwide; porcine coronavirus (transmissible gastroenteritis, TGE) and bovine coronavirus, which both result in diarrhoea in young animals.
Feline coronavirus коронавирус в сингапуре информация has two forms, feline enteric coronavirus is a pathogen of minor clinical коронавирус в сингапуре информация significance, but spontaneous mutation of this virus can result in feline infectious peritonitis (FIP), a disease associated with high mortality. There are also two types of canine coronavirus (CCoV), one that causes mild gastrointestinal disease and one that has been found to cause respiratory disease. Mouse hepatitis virus (MHV) коронавирус в сингапуре информация is a coronavirus that causes an epidemic murine illness with high mortality, especially among colonies of laboratory mice. Coronaviruses are divided into four groups, as shown below: Alpha Canine coronavirus (CCoV) Feline coronavirus (FeCoV) Human coronavirus 229E (HCoV-229E) Porcine epidemic diarrhoea virus (PEDV) Transmissible gastroenteritis virus (TGEV) Human Coronavirus коронавирус в сингапуре информация NL63 (NL or New Haven) Beta Bovine coronavirus (BCoV) Canine respiratory coronavirus (CRCoV)—Common in SE Asia and Micronesia Human coronavirus OC43 (HCoV-OC43) Mouse hepatitis virus (MHV) Porcine haemagglutinating encephalomyelitis virus (HEV) Rat coronavirus (Roy). Rat Coronavirus is quite prevalent in Eastern Australia where, as of March/April 2008, it has been found among native and feral rodent colonies. (No common name as of yet) (HCoV-HKU1) ?Severe acute respiratory syndrome coronavirus (SARS-CoV) Middle East respiratory syndrome coronavirus (MERS-CoV) Gamma Infectious bronchitis virus (IBV) Turkey coronavirus (Bluecomb коронавирус в сингапуре информация disease virus) Pheasant coronavirus Guinea fowl coronavirus Delta Bulbul coronavirus (BuCoV) Thrush coronavirus (ThCoV) Munia coronavirus (MuCoV) Porcine coronavirus (PorCov) HKU15 The variant replicase gene of the coronavirus of the present invention may be derived from an alphacoronavirus such as TGEV; a betacoronavirus such as MHV; or a коронавирус в сингапуре информация gammacoronavirus such as IBV. As used herein the term “derived from” means that the replicase gene comprises substantially the same nucleotide sequence as the wild-type replicase gene of the relevant coronavirus.
For example, the variant replicase gene коронавирус в сингапуре информация of the present invention may have up to 80%, 85%, 90%, 95%, 98% or 99% identity with the wild type replicase sequence. The variant coronavirus replicase gene encodes a protein comprising a mutation in one or коронавирус в сингапуре информация more of non-structural protein (nsp)-10, nsp-14, nsp-15 or nsp-16 when compared to the wild-type sequence of the non-structural protein.
IBV Avian infectious bronchitis (IB) коронавирус в сингапуре информация is an acute and highly contagious respiratory disease of chickens which causes significant economic losses. The disease is characterized by respiratory signs including gasping, коронавирус в сингапуре информация coughing, sneezing, tracheal rales, and nasal discharge. In young chickens, severe respiratory коронавирус в сингапуре информация distress may occur. In layers, respiratory distress, nephritis, decrease in egg production, коронавирус в сингапуре информация коронавирус в сингапуре информация and loss of internal egg quality and egg shell quality are common.
In broilers, coughing and rattling are common clinical signs, rapidly spreading in all the birds of the premises. Mortality varies depending on age, virus strain, and secondary infections but may be up to 60% in non-vaccinated flocks. The first IBV serotype to be identified was Massachusetts, but in the United States several serotypes, including Arkansas and Delaware, are currently circulating, in addition to the originally identified Massachusetts type. The IBV strain Beaudette was derived following at least 150 passages in chick embryos. IBV Beaudette is no коронавирус в сингапуре информация longer pathogenic for hatched chickens but rapidly kills embryos. H120 is a commercial live attenuated IBV Massachusetts serotype vaccine strain, attenuated by approximately 120 passages in embryonated chicken eggs. H52 is another Massachusetts vaccine, and represents коронавирус в сингапуре информация an earlier and slightly more pathogenic passage virus (passage 52) during the development of H120. It is sometimes known as “Chinese QX” as it коронавирус в сингапуре информация was originally isolated following outbreaks of disease in the Qingdao region in China коронавирус в сингапуре информация in the mid 1990s. Since that time the virus has crept towards Europe. From 2004, severe egg production issues have been identified with a very similar virus in parts of Western Europe, predominantly in the Netherlands, but also reported from Germany, France, Belgium, Denmark and in the UK. The virus isolated from the Dutch cases was identified by the Dutch Research Institute at Deventer as a new strain that they called D388. The коронавирус в сингапуре информация Chinese connection came from further tests which showed that the virus was 99% similar to the Chinese QX viruses. A live attenuated QX-like IBV vaccine strain has now been developed. IBV is an enveloped virus that коронавирус в сингапуре информация replicates in the cell cytoplasm and contains an non-segmented, single-stranded, positive sense RNA genome. IBV has a 27.6 kb RNA genome and like all coronaviruses contains the four structural proteins; spike glycoprotein (S), small membrane protein (коронавирус в сингапуре информация E), integral membrane protein (M) and nucleocapsid protein (N) which interacts with the genomic RNA. The genome is organised in the following manner: 5?коронавирус в сингапуре информация UTR—polymerase (replicase) gene—structural protein genes (S-E-M-N)—UTR 3?; where the UTR are коронавирус в сингапуре информация untranslated regions (each ?500 nucleotides in IBV). The lipid envelope contains three membrane proteins: S, M and E. The IBV S protein is a type I glycoprotein which oligomerizes in the endoplasmic reticulum and is assembled into homotrimer inserted in the virion membrane via the transmembrane domain and is коронавирус в сингапуре информация associated through non-covalent interactions with the M protein.
Following incorporation into coronavirus particles, the S protein is responsible for binding to the target cell receptor and fusion of the viral and cellular membranes. The S glycoprotein consists of four domains: a signal sequence that is cleaved during synthesis; the ectodomain, which is present on the outside of the virion particle; коронавирус в сингапуре информация the transmembrane region responsible for anchoring the S protein into the lipid bilayer of the virion particle; and the cytoplasmic tail. All coronaviruses also encode a set of accessory protein genes of unknown function that are not required for replication in vitro, but may play a role in pathogenesis. IBV encodes two accessory genes, genes 3 and 5, which both express two accessory proteins 3a, 3b and 5a, 5b, respectively. The variant replicase коронавирус в сингапуре информация gene of the coronavirus of the present invention may be derived from an IBV. For example the IBV may be IBV Beaudette, H120, H52, IB QX, D388 or M41. M41 is a prototypic Massachusetts serotype that was isolated in the USA in 1941.
It is an isolate used in many labs throughout the world as a pathogenic lab stain and can be obtained from ATCC (VR-21™). Attenuated variants are also used by several vaccine producers as IBV vaccines against Massachusetts serotypes causing problems in the field.
