Genus: Teschovirus


Genus: Teschovirus

Distinguishing features

The genus is distinguished on the basis of genetic characters.

Virion

Morphology

No surface morphology is visible by EM.

Physicochemical and physical properties

Virions are stable at acid pH. Buoyant density in CsCl is 1.33 g cm-3. Empty capsids are often observed in virus preparations.

Nucleic acid

Genome (Zell et al., 2001, Buitrago et al., 2010, Boros et al., 2012b, Yang et al., 2018, Oba et al., 2018): >7,110 nt (5′-proximal sequence missing) (5′-UTR: >335 nt; ORF: 6,600–6,711; 3′-UTR: 67 nt). Teschoviruses have a type IV IRES of about 290 nt which is functional in the absence of eIF-4G. The location of the cre is thought to be within the 2C region. 

Genome organization and replication

Genome layout

VPg+5′-UTRIRES-IV-[L-1A-1B-1C-1D-2Anpgp/2B-2C/3A-3B-3C-3D]-3′-UTR-poly(A)

The deduced polyprotein varies from 2,199–2,236 aa. The function of the leader polypeptide is unknown. 2A is a short polypeptide with an NPG↓P motif. 

Biology

Clinical manifestations may include a polioencephalomyelitis (“Teschen/Talfan disease”, also known as teschovirus encephalomyelitis), which may vary in severity. The viruses have been associated with a number of disease syndromes, including reproductive and gastrointestinal disorders. Domestic pigs and wild boars are the only known hosts. Natural inter-species recombination has been described. Nineteen genetic types are distinguished by means of phylogenetic analysis (Teschovirus A: teschovirus A1 to -A14, Teschovirus B: teschovirus B1 to -B3; recombinant viruses: teschovirus A15CP-BPol, teschovirus A16CP-BPol).

Antigenicity

Porcine teschoviruses are divided into 13 types (PTV-1 to -13) which are distinct in cross-neutralization tests (where tested).

Derivation of names

Teschovirus: from Teschen disease; named after the Moravian-Silesian town Teschen (now Těšín at the Czech/Polish border.

Species demarcation criteria

Members of a species of the genus Teschovirus:

  • are less than 20% divergent in polyprotein aa sequence
  • are less than 30% divergent in P1 aa sequence
  • are less than 10% divergent in 2C+3CD aa sequence
  • share a common genome organization
  • share a natural host range

Member species

Exemplar isolate of the species
SpeciesVirus nameIsolateAccession numberRefSeq numberAvailable sequenceVirus Abbrev.
Teschovirus Ateschovirus A1; porcine teschovirus 1F65AJ011380NC_003985Complete genomeTV-A1; PTV-1
Teschovirus Ateschovirus A2; porcine teschovirus 2T80AF296087Complete genomePTV-2
Teschovirus Ateschovirus A3; porcine teschovirus 3O 2bAF296088Complete genomePTV-3
Teschovirus Ateschovirus A4; porcine teschovirus 4PS 36AF296089Complete genomePTV-4
Teschovirus Ateschovirus A5; porcine teschovirus 5F 26AF296090Complete genomePTV-5
Teschovirus Ateschovirus A6; porcine teschovirus 6PS 37AF296091Complete genomePTV-6
Teschovirus Ateschovirus A7; porcine teschovirus 7F 43AF296092Complete genomePTV-7
Teschovirus Ateschovirus A8; porcine teschovirus 8UKG/173/74AF296093Complete genomePTV-8
Teschovirus Ateschovirus A9; porcine teschovirus 9Vir 2899/84AF296094Complete genomePTV-9
Teschovirus Ateschovirus A10; porcine teschovirus 10Vir 460/88AF296095Complete genomePTV-10
Teschovirus Ateschovirus A11; porcine teschovirus 11DresdenAF296086Complete genomePTV-11
Teschovirus Ateschovirus A12; porcine teschovirus 12CC25 (Spain/2005)JF724001Partial genomePTV-12
Teschovirus Ateschovirus A13; porcine teschovirus 13wild boar/WB2C-TV/2011/HUNJQ429405Complete genomePTV-13
Teschovirus Ateschovirus A14; porcine teschovirus 14JPN/Mol2-2-2/2015LC386160Partial genomePTV-14
Teschovirus Bteschovirus B1HuN41MG875515Complete genomeTV-B1
Teschovirus Bteschovirus B2JPN/Ishi-Ta2/2016-GLC386157Complete genomeTV-B2
Teschovirus Bteschovirus B3HuN42MG875516Partial genomeTV-B3

Virus names, the choice of exemplar isolates, and virus abbreviations, are not official ICTV designations.