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): >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′-UTR^IRES-IV-[L/1A-1B-1C-1D-2A^npgp/2B-2C/3A-3B-3C-3D]-3′-UTR-poly(A)

The deduced polyprotein varys from 2,199–2,236 aa. The function of the leader polypeptide is unknown. 2A is a short foot-and-mouth disease virus-like polypeptide with NPG↓P motif. 

Antigenicity

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

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.

Species demarcation criteria

There is only a single species in the genus.

Member species

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

Derivation of names

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

Related, unclassified viruses 

Virus names and virus abbreviations are not official ICTV designations.

Phylogenetic analysis indicates that these viruses may be members of a novel Teschovirus species.