Picobirnavirus

Picobirnavirus
Virus classification
Group: Group III (dsRNA)
Order: Unassigned
Family: Picobirnaviridae
Genus: Picobirnavirus
Type species
Human picobirnavirus
Species

Calf picobirnavirus
Chicken picobirnavirus
Foal picobirnavirus
Giant anteater picobirnavirus
Guinea pig picobirnavirus
Hamster picobirnavirus
Human picobirnavirus
Pig picobirnavirus
Rabbit picobirnavirus
Rat picobirnavirus

Picobirnavirus is a genus of dsRNA virus. It may be implicated in gastroenteritis in animals including humans.

The viruses have only been isolated from amniotes to date.

History

First detection of Picobirnavirus (PBV) was in humans and black-footed pigmy rice rats in 1988.[1]

Virology

The virons have a diameter of 35–40 nanometers with a triangulation number (T) = 1, 3 or 4.

The genome is a bipartate and double stranded RNA. It includes a segment 1 – 2.5 (2.2–2.7) kilobases (kb) length and a segment 2 – 1.7 (1.2–1.9) kb in length. The capsid protein gene is encoded by the second open reading frame of the larger genomic segment.

These viruses are divided into two genogroups on the basis of the sequence of segment 2.

They have been isolated from humans and other mammals, as well as birds and squamates.[2] Their role in pathogenicity if any is not yet clear.

Taxonomy, Classification, and Nomenclature

PBV was initially thought to belong to family Birnaviridae but later confirmed to differ with respect to host, virion size, capsid, RNA polymerase, genome size, and organization. Now PBV has been classified distinctly[3] A new viral family named Picobirnaviridae under the proposed order “Diplornavirales” was created to accommodate this unique virus and a complete new taxonomic order was assigned . This new viral family is composed of only one viral genus, Picobirnavirus. The two species under the genus are Human Picobirnavirus and Rabbit Picobirnavirus, where the former one is nominated as a type species and the latter one as designated species by the International Committee on Taxonomy of Viruses in 2008. The nomenclature of the virus has been derived from its size and genome characteristics: the prefix “pico” signifies the small diameter of the viral particle (35 nm) and “birna” signposts a genome composed of two segments of dsRNA.

References

  1. ↑ Pereira HG, Flewett TH, Candeias JAN, Barth OM (1988). A virus with a bisegmented double-stranded RNA genome in rat (Oryzomys nigripes) intestines. J Gen Virol 69(11):2749–2754
  2. ↑ Smits SL, van Leeuwen M, Schapendonk CM, Schürch AC, Bodewes R, Haagmans BL, Osterhaus AD (2012) Picobirnaviruses in the human respiratory tract. Emerg Infect Dis 18(9):1539–40. doi: 10.3201/eid1809.120507
  3. ↑ Malik YS, Kumar N, Sharma K, Dhama K, Shabbir MZ, Ganesh B, Kobayashi N, Banyai K (2014). Epidemiology, phylogeny, and evolution of emerging enteric Picobirnaviruses of animal origin and their relationship to human strains.Biomed Res Int. 780752. doi: 10.1155/2014/780752

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