Orthonairovirus

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Orthonairovirus
Systematics
Classification : Viruses
Area : Riboviria
Empire : Orthornavirae
Phylum : Negarnaviricota
Subphylum : Polyploviricotina
Class : Ellioviricetes
Order : Bunyavirales
Family : Nairoviridae
Genre : Orthonairovirus
Taxonomic characteristics
Genome : (-) ssRNA segmented
Baltimore : Group 5
Symmetry : helical
Cover : available
Scientific name
Orthonairovirus
Left
NCBI  Taxonomy: 1980517
ViralZone ( ExPASy , SIB): 251

Orthonairovirus (formerly Nairovirus ) is a genus of viruses in the family of the Nairoviruses ( Nairoviridae ) from the order of the Bunyaviruses ( Bunyavirales ), which includes representatives with a genome of segmented, circular RNA of negative polarity . The name comes from the Nairobi sheep disease, which affects the gastrointestinal tract of sheep and goats. The vast majority, if not all, of viruses in this genus are tick- borne, affect vertebrates, and especially humans.

Genome

The genome of the viruses in the genus Orthonairovirus consists of single-stranded RNA with negative polarity . The full genome is approximately 17,100–22,800  nt long and is divided into three segments: large (L), medium (M), and small (S). The large segment is approximately 11,000-1,4400 nt long and codes for the viral polymerase . The middle segment is about 4,400-6,300 nt long and codes for the glycoproteins Gn and Gc. The small segment is about 1,700–2,100 nt long and codes for the nucleocapsid protein.

The genome has terminally redundant sequences with the sequences repeated at both ends. The sequences are at the 5 'end: UCUCAAAGA and at the 3' end: AGAGUAUCU.

construction

The virions (virus particles) of the viruses of this genus are spherical (spherical). They have a diameter of about 80-120 nm, with 50% of their weight being assigned to proteins and 20-30% of their weight to lipids . The ribonucleocapsid is filamentous and has a length of about 200-300 nm and a width of about 2-2.5 nm.

These nucleocapsids are made of a single shell with protrusions of glycoproteins protruding from their surface. These protrusions evenly cover the surface of the virion and are about 5-10 nm long.

Multiplication

Orthonairoviruses attach themselves to the host receptor with their Gn-Gc glycoprotein dimer. The virus is then absorbed into the host cell via vesicles ( endocytosis ). The ribonucleocapsid segments are released into the cytoplasm (cell fluid), and transcription begins. Transcription and replication occur within the cell, and the newly synthesized virions are released by budding .

transmission

Members of this genus virus infect many different vertebrates ( Vertebrata ) and by ticks transmit. They can be found anywhere in the world where arthropods ( arthropods ) as an intermediary (vectors) and vertebrates arrive together (as hosts).

Infection in humans

So far, only four viruses of this genus have been recognized as human pathogens:

A fifth virus - the Erve virus - could also be pathogenic for humans.

Systematics

The genus is conventionally classified into at least nine serogroups . The Hughes and Sakhalin serogroups appear to be sister groups. A phylogenetic analysis has shown that these viruses fall into two main monophyletic groups, which are named after their tick vectors (carriers) in the hard ( Ixodidae ) and soft ( Argasidae ). Fossil and phylogenetic data date the split into these two groups between 92 and 120 million years ago. This suggests that the Orthonairoviruses have been associated with these ticks as carriers for over 100 million years ( coevolution ). In addition, nairoviruses, which are transmitted by ticks of the genera Argas , Carios and Ornithodorus , form three separate monophyletic lineages, which also supports the proposal for coevolution.

As a type species, the Dugbe orthonairovirus has now replaced the Nairobi sheep disease orthonairovirus . The following classification of the species of the genus Orthonairovirus corresponds to that of the International Committee on Taxonomy of Viruses (ICTV) as of November 2018; Abbreviations according to ViralZone are from 2016; the species are also classified according to sreo groups. The virus names (subspecies etc.) follow the 9th report of the ICTV and the update from 2018:

The Khasan virus (also Khazan virus, KHAV) previously listed here is now mostly placed in the virus genus Phlebovirus (Uukuniemi serocomplex around the species Uukuniemi phlebovirus ).

Web links

Individual evidence

  1. ↑ ICTV Master Species List 2018b.v2 . MSL # 34, March 2019
  2. ↑ a b ICTV: ICTV Taxonomy history: Akabane orthobunyavirus , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
  3. ↑ ICTV 9th Report (2011) Bunyaviridae ( en , html) Retrieved on February 11, 2019: "Nairo: from Nairobi sheep disease, first reported disease caused by member virus."
  4. ^ A b c d M.B. Crabtree, R. Sang, BR Miller: Kupe virus, a new virus in the family bunyaviridae, genus nairovirus, kenya. In: Emerging infectious diseases. Volume 15, number 2, February 2009, pp. 147-154, doi : 10.3201 / eid1502.080851 , PMID 19193256 , PMC 2657624 (free full text).
  5. ↑ a b c d e f g Büchen-Osmond, Cornelia. "00.011.0.03. Nairovirus." ICTVdb Virus Descriptions. April 25, 2006. International Committee on Taxonomy of Viruses. 17 Apr 2009.
  6. ↑ a b c d e f g Nairovirus , on: ViralZone , Swiss Institute of Bioinformatics (SIB)
  7. ↑ E Honig, JC Osborne, ST Nichol: The high genetic variation of viruses of the genus Nairovirus reflects the diversity of their predominant tick hosts . In: Virology , 318 (1), 2004, pp. 10-16, PMID 14972529
  8. ↑ Master Species List 2018a v1. ICTV , MSL including all taxa updates since the 2017 release. Fall 2018 (MSL # 33)
  9. ↑ Viral zone : ICTV 2016 Master Species List # 31 with Acronyms (Excel XLSX) , SIB Swiss Institute of Bioinformatics
  10. ↑ John PM Clerx, Jordi Casals, David HL Bishop: Structural Characteristics of Nairoviruses (Genus Nairovirus, Bunyaviridae) . In: Journal of General Virology , 55, 1981, pp. 165-178, PMID 7299367 .
  11. ↑ ICTV : Negative Sense RNA Viruses: Bunyaviridae (2011) , in: 9th report of the ICTV (2011)
  12. ↑ Piet Maes, S. Adkind, SV Alkhovsky et al .: Taxonomy of the order Bunyavirales: second update 2018. In: Arch Virol , Springer, Vienna (2019), doi: 10.1007 / s00705-018-04127-3 , ISSN 0304 -8608
  13. ↑ P27317 (NCAP_CCHFV). Nucleoprotein of the CCHFV isolate C68031. UniProtKB
  14. ↑ DK L'vov et al .: Genetic characterization of the Geran virus (GERV, Bunyaviridae, Nairovirus, Qalyub group) isolated from the ticks Ornithodoros verrucosus Olenev, Zasukhin and Fenyuk, 1934 (Argasidae) collected in the burrow of Meriones erythrourus Gray, 1842 in Azerbaijan . In: Vopr Virusol. , 2014, 59 (5), S: 13-18, PMID 25895205
  15. ↑ Recommendation of the ZKBS on the risk assessment of the Erve virus as a donor or recipient organism for genetic engineering work according to § 5 Paragraph 1 GenTSV , Federal Office for Consumer Protection and Food Safety
  16. ↑ Al'khovskiĭ SV, L'vov DK, Shchelkanov MIu, Shchetinin AM, Deriabin PG, Samokhvalov EI, Gitel'man AK, Botikov AG: The taxonomy of the Khasan virus (KHAV), a new representative of phlebovirus genera (Bunyaviridae) , isolated from the ticks haemaphysalis longicornis (Neumann, 1901) in the Maritime Territory (Russia) , in: Vopr Virusol. September / October 2013; 58 (5): 15-18, PMID 24640166 (article in Russian, only abstract in English)
  17. ↑ ICTV: ICTV Taxonomy history: Uukuniemi phlebovirus , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)