Lyssavirus

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This article is about the rabiform virus. For the hemorrhagic fever-causing virus, see
Lassa virus
.

Lyssavirus
Colored transmission electron micrograph of "Australian bat lyssavirus". The bullet-like objects are the virions, and some of them are budding off from a cell.
Colored
transmission electron micrograph of Australian bat lyssavirus
. The bullet-like objects are the virions, and some of them are budding off from a cell.
Virus classification Edit this classification
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum:
Negarnaviricota
Class: Monjiviricetes
Order: Mononegavirales
Family: Rhabdoviridae
Genus: Lyssavirus
Species

Lyssavirus (from the Greek λύσσα lyssa "rage, fury, rabies" and the Latin vīrus)[1][2] is a genus of RNA viruses in the family Rhabdoviridae, order Mononegavirales. Mammals, including humans, can serve as natural hosts.[3][4] The genus Lyssavirus includes the rabies virus traditionally associated with the disease of the same name.

Taxonomy

Genus Lyssavirus: species and their viruses[5][6]
Genus Phylogroup Species Virus (Abbreviation)
Lyssavirus I Aravan lyssavirus Aravan virus (ARAV)
Australian bat lyssavirus Australian bat lyssavirus (ABLV)
Bokeloh bat lyssavirus Bokeloh bat lyssavirus (BBLV)
Duvenhage lyssavirus
Duvenhage virus
(DUVV)
European bat 1 lyssavirus
European bat lyssavirus 1
(EBLV-1)
European bat 2 lyssavirus
European bat lyssavirus 2
(EBLV-2)
Gannoruwa bat lyssavirus Gannoruwa bat lyssavirus (GBLV)
Irkut lyssavirus Irkut virus (IRKV)
Khujand lyssavirus Khujand virus (KHUV)
Madagascar bat lyssavirus Madagascar bat lyssavirus (MABV)
Rabies lyssavirus
 		Rabies virus (RABV)
II Lagos bat lyssavirus
Lagos bat virus
(LBV)
Mokola lyssavirus
Mokola virus
(MOKV)
Shimoni bat lyssavirus
Shimoni bat virus
(SHIBV)
III West Caucasian bat lyssavirus West Caucasian bat virus (WCBV)
IV Ikoma lyssavirus Ikoma lyssavirus (IKOV)
Lleida bat lyssavirus Lleida bat lyssavirus (LLEBV)

Virology

Structure

Lyssavirions are enveloped, with bullet shaped geometries. These virions are about 75 nm wide and 180 nm long.[3] Lyssavirions have helical symmetry, so their infectious particles are approximately cylindrical in shape. This is typical of plant-infecting viruses. Virions of human-infecting viruses more commonly have cubic symmetry and take shapes approximating regular polyhedra.[citation needed]

The structure consists of a spiked outer

ribonucleocapsid complex region, consisting of the genome associated with other proteins.[citation needed
]

Genome

Lyssavirus genomes consist of a negative-sense, single-stranded RNA molecule that encodes five viral proteins: polymerase L, matrix protein M, phosphoprotein P, nucleoprotein N, and glycoprotein G. Genomes are linear, around 11kb in length.[3]

Based on recent phylogenetic evidence, lyssaviruses have been categorized into seven major species. In addition, five more species have recently been discovered: West Caucasian bat virus, Aravan virus, Khujand virus, Irkut virus and Shimoni bat virus.[7][8] The lyssavirus genus can be divided into four phylogroups based upon DNA sequence homology. Phylogroup I includes viruses, such as Rabies virus, Duvenhage virus, European bat lyssavirus types 1 and 2, Australian bat lyssavirus, Khujand virus, Bokeloh bat lyssavirus, Irkut virus, and Aravan virus. Phylogroup II contains Lagos bat virus, Mokola virus, and Shimoni bat virus. West Caucasian bat lyssavirus is the only virus that is a part of phylogroup III. Ikoma lyssavirus and Lleida bat lyssavirus are examples in phylogroup IV. West Caucasian bat lyssavirus was classified within its own phylogroup because it is the most divergent lyssavirus that has been discovered.[9]

Genus Structure Symmetry Capsid Genomic arrangement Genomic segmentation
Lyssavirus Bullet-shaped Enveloped Linear Monopartite

Evolution

Phylogenetic studies suggest that the original hosts of these viruses were bats.

Palearctic origin (85% likelihood) for these viruses.[13] Date estimates (95% likelihood) for the most recent common ancestor were very broad – between 3,995 and 166,820 years before present – which suggests there is further work to be done in this area. Although bats evolved in the Palearctic,[14] their origins antedate that of the lyssaviruses by millions of years, which argues against their co-speciation. The evolution rate in the N gene in the Africa 2 lineage has been estimated to be 3.75×10−3 substitutions per site per year.[15]
This rate is similar to that of other RNA viruses.

Life cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the viral G glycoproteins to host receptors, which mediates clathrin-mediated endocytosis. Replication follows the negative stranded RNA virus replication model. Negative stranded RNA virus transcription, using polymerase stuttering, is the method of transcription. The virus exits the host cell by budding and by tubule-guided viral movement. Wild mammals, especially bats and certain carnivores, serve as natural hosts. Transmission routes are typically via bite wounds.[3]

Genus Host details Tissue tropism Entry details Release details Replication site Assembly site Transmission
Lyssavirus bats, Crocidura shrews and certain carnivores Neurons Clathrin-mediated endocytosis Budding Cytoplasm Cytoplasm Bite wounds

Testing

As of 2018 the

Real-time PCR-based tests which have higher sensitivity and objective diagnostic thresholds and allow samples to be stored at room temperature have been promising since 2005, but require a real-time PCR machine and skilled workers with experience in molecular diagnostics. In an international evaluation a single TaqMan LN34 assay could detect Lyssavirus with high sensitivity (99.90%) across the genus and high specificity (99.68%) when compared to the DFA test. It will become the primary post-mortem rabies diagnostic test where possible.[16]

Epidemiology

Classic

Mokola virus.[17]

See also

  • Bat-borne virus

References

  1. Perseus Project
    .
  2. Perseus Project
    .
  3. ^
    ExPASy
    . Retrieved 15 June 2015.
  4. ^ ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015.
  5. PMID 27216929
    .
  6. ^ "Genus: Lyssavirus". International Committee on Taxonomy of Viruses (ICTV). Retrieved 18 December 2018.[dead link]
  7. ^ Virus Taxonomy: 2013 Release. ictvonline.org
  8. PMID 15896400
    .
  9. PMID 12367747
    .
  10. PMID 21601050
    .
  11. PMID 34578307
    .
  12. S2CID 226276694
    .
  13. PMID 28036390
    .
  14. S2CID 25912333
    .
  15. PMID 28818621
    .
  16. PMID 29768505
    .
  17. ^ WHO Rabnet/CDC Map Production (2008). "Rabies, countries or areas at risk". World Health Organization. Archived from the original on 9 October 2010.

Further reading

External links

Wikimedia Commons has media related to Lyssavirus.