Ebola virus

You know five species belonging to this genus and four of these are responsible for the disease Ebola (in English "ebola virus disease" or EVD ") that affects humans with a hemorrhagic fever with a very high fatality rate. The five species virus recognized by the International Committee on Taxonomy of Viruses are named after the regions where they have been identified for the first time.
The species are: Bundibugyo ebolavirus, Reston ebolavirus, Sudan ebolavirus, Taï Forest ebolavirus (originally Côte d'Ivoire ebolavirus) and Zaire ebolavirus. Zaire ebolavirus is the reference species for the genus Ebolavirus and is constituted by a single known strain, simply called "Ebola virus", which is characterized by the highest fatality rate of Ebolavirus and is also responsible for the largest number of outbreaks Ebola attributable to the genre, including the outbreak of Ebola haemorrhagic fever in Zaire in 1976 and the outbreak of Ebola haemorrhagic fever in West Africa in 2014, which is the one that has so far caused the greatest number of victims.
The Ebolavirus have been described for the first time since the outbreak of haemorrhagic fever broke out in southern Sudan in June 1976 and in Zaire in August 1976. [2]
The name comes from the River Ebolavirus Ebola in Zaire (now the Democratic Republic of Congo), a tributary of the Congo River, where the outbreak occurred in 1976, while the suffix indicates taxonomic -virus be a viral genus. [1] The genus was introduced in 1998 as a "kind of viruses that look like the Ebola virus". [3] [4] In 2002, the genus name was changed to Ebolavirus [5] [6] and in 2010, the genre was amended from some members. [ 1] The Ebolavirus are closely connected with Marburgvirus. Taxonomic notes
Under the rules for the nomenclature of taxon defined by the International Committee on Taxonomy of Viruses (ICTV), the genus name is written Ebolavirus always capitalized and italicized. It should never be abbreviated and should be preceded by the word "gender". In the terminology of international English, when you call collectively the members of the genus, do not use the upper case, italics and the article (ebolaviruses). [1]Criteria for inclusion in the genre
A virus of the family is a member of the genus Filoviridae Ebolavirus if [1]

    its genome has several overlapping genes
    his fourth gene (GP) encodes four proteins (SGP, ssGP, Δ-peptide and GP1,2) using a cut co-transcriptional for ssGP and GP1,2 and proteolytic cleavage to get SGP and Δ-peptide
    the peak of infectivity of its virions is associated with particles of ≈805 nm in length
    its genome differs from that of the Marburg virus quantity ≥50% and that of the Ebola virus by an amount <50% at the nucleotide level
    its virions do not show nearly antigenic cross-resistance with virions marburg
Key Features
The viruses of this genus are transmitted through contact with the biological fluids of an infected, even during its gestation period (30 days before symptoms); would be theoretically possible to contract the virus by touching one of these sweat, also filed, a sick person, even if it is a probability rather remote. Potentially these viruses could be used as a biological weapon: as agents of bioterrorism, these viruses are classified in category A. [7] The effectiveness as an agent of biological warfare virus of this kind is however compromised by the high mortality and its level Contagion: typical epidemic could spread through a small village or hospital, infecting the entire community without being able to find other potential guests, then dying before reaching a wider community.
One of the known species of ebolavirus has a transmissibility type plane: the Reston ebolavirus species (from the city of Reston, Virginia, where he was identified in a type of monkey).VirologyMorphology
The inquiry in the electron microscope of the species belonging to the genus Ebolavirus shows the characteristic structure of filamentous filoviruses. [8] The species Ebola virus VP30 EBOV is constituted by a chain of 288 amino acids. [8] The virions generally have a tubular structure variable: may take the form of a crook, eyelet, or U 6, coiled, circular or branched. However the laboratory techniques of purification such as centrifugation may affect the morphological appearance. [8] The virions generally measure 80 nm in diameter. [8] They have variable sizes, typically around 1000 nm, but can reach 1400 nm in length . In the center of the virion is a structure called the nucleocapsid, consisting of the viral genomic RNA and a protein complex NP, VP35, VP30 and L. The virion has a diameter of 40-50 nm and a central channel of 20-30 nm in diameter. A glycoprotein (GP) virus is present on the viral membrane, derived from the host cell membrane. Between the membrane and nucleocapsid, the so-called matrix, are allocated to the viral proteins VP40 and VP24.Genome
Each virion contains a linear molecule anti-sense RNA, approximately 18,959 nucleotides in length even up to 18,961. The 3 'end is not poliadenilata, and 5' is devoid of the cap. It was found that 472 nucleotides from the 3 'UTR, and 731 nucleotides from the 5' UTR are sufficient for replication. [8] It is able to encode seven structural proteins and a non-structural. The coding region is 3 '- leader - NP - VP35 - VP40 - GP / SGP - VP30 - VP24 - L - trailer - 5'; leader and trailer regions not being transcribed carrying signals important for the control of transcription, replication and assembly of the viral genome in the new virion. The genomic material in itself is not infectious due to viral protein, but the RNA dependent RNA polymerase, are necessary for the transcription of the viral genome in the mRNA, as well as for the replication of the viral genome.Life cycle

    The viruses attack the receptors of the host by Peplomer glycoprotein veicolandosi in vesicles by endocytosis into the host cell.

    Fusion of the viral membrane with the vesicle membrane; the nucleocapsid is released into the cytoplasm.

    The anti-sense ssRNA incapsidato is used as a template for the synthesis (3 '- 5') of polyadenylated mRNA, monocistronico.

    MRNA translation into viral proteins using the facilities of the host cell.

    Post-translational processing of viral proteins. By cleavage of GP0 (precursor glycoprotein) derived GP1 and GP2, which are abundantly glycosylated. The assembly of these two molecules, first in heterodimers, and trimers then constitutes the surface of the Peplomer. A precursor glycoprotein secretion undergoes a cleavage in SGP and delta peptide, both of which released from the cell.

    With the increase in the protein level viral translation from switching to replication. Using the anti-sense RNA as a template, is synthesized a complementary ssRNA +, used as a template for further synthesis of the new (-) ssRNA genome, rapidly incapsidato.

    The newly formed nucleocapsid and envelope proteins are associated with the plasma membrane of the host cell; the release of virions occurs by budding.
Reserves viral
Despite numerous studies, the nature reserve of Ebolavirus not yet been identified. Between 1976 and 1998, no ebolavirus was found in the 30,000 species of mammals, birds, reptiles, amphibians and arthropods collected in the affected regions, [9] with the exception of the genetic material found in six rodents (Peters's mouse and species Praomys) and a shrew (Sylvisorex ollula) retrieved in the Central African Republic in 1998. [10] ebolavirus were discovered in the carcasses of gorillas, chimpanzees and gazelles during the epidemic of 2001 and 2003 (the carcasses were the source of the epidemic early human ), but the high rate of infection in these species precludes the possibility of turning into the reserve. [9]
Even plants and birds were considered viral reserves; However, bats are considered the best candidates. [11] Some bats were known to reside in the cotton factory in which patients suspects epidemics of 1976 and 1979 and who were working were also implicated in outbreaks of Marburg in 1975 and 1980. [9] Among the 24 species of plants and 19 species of vertebrates experimentally inoculated with ebolavirus, only in bats occurred infection. [12] The absence of clinical signs in these bats is characteristic of the species-reserve . In 2002-03, a survey of 1,030 animals from Gabon and the Republic of Congo that included 679 bats identified RNA from ebolavirus in 13 of these (Hammer-headed bat, Franquet's epauletted fruit bat and Little collared fruit bat). [13] The bats are also known to be the subject of numerous viral virus as nipahvirus, hendravirus and lyssavirus. Recently [when?] Has been identified [citation needed] one of the receptors used by the virus, TIM-1, which would be important for the attack to some epithelial cells (possible route of entry of the virus). It seems that ebolavirus have developed in some caves of Kenya. [14].
In 2012 it was discovered in China the first insulation bats of Reston filovirus species as a result of serological tests conducted in a population of bats Chinese. The Reston ebolavirus species, discovered in the Philippines, is the only species of ebolavirus identified in Asia to date. [15] Furthermore, in 353 healthy Borneo orangutans (Pongo pygmaeus) in the island Kalimantan in Indonesia, in the period from December 2005 to December 2006, found a posività serological 18.4% (65/353) and 1.7% (6/353) of the samples examined respectively for EBOV (Ebola) and MARV (Marburg). Most EBOV-positive sera showed a serological similarity to species found in Zaire, Sudan, Ivory Coast, or for viruses Bundibugyo, that have been found so far only in Africa. The authors of the research suggest the existence of multiple species of filovirus, or unknown viruses related to filovirus, in Indonesia, some of which are similar to viruses serologically EBOV Africans, indicating a possible presence of reservoirs of virus not yet identified between populations of orangutans in Indonesia. [16]
The researcher Berlin Gretchen Vogel, the editorial staff of the journal Science, published on the same April 11, 2014 an editorial entitled: (Are Bats Ebola Spreading Across Sub-Saharan Africa?) Are the bats that spread the Ebola virus in the whole 'Sub-Saharan Africa ?; suggesting, with this article, as the spread of the virus endangers the people who live in forested areas of the entire sub-Saharan Africa. [17]