Genus: Torchivirus


Genus: Torchivirus

Distinguishing features

The genus is distinguished on the basis of genetic characters.

Virion

Morphology

No surface morphology is visible by EM (Heuser et al., 2014).

Nucleic acid

Incomplete genome (Farkas et al., 2015): 7,077 nt (5′-UTR: 192 nt; ORF: 6,654 nt; 3′-UTR: 231 nt). The location of the cre has not been identified.

Genome organization and replication

Genome layout:

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

The deduced polyprotein is of 2,218 amino acids. The function of the L protein is unknown. Protein 2A is of 145 amino acids, exhibits a NPG↓P motif and lacks similarity to other picornaviruses.

Antigenicity

See discussion under family description.

Biology

Torchiviruses were isolated from various tortoise species (Testudo graeca, Testudo hermanni, Geochelone sulcata, Pyxis arachnoides) in Hungary and Germany. Viruses were propagated in Terrapene heart permanent cell line (ATCC CCL-50). Torchivirus infections have been associated with various clinical signs and pathological lesions including softening of the carapax of young animals, diphtheroid necrotizing stomatitis and pharyngitis, rhinitis, pneumonia, conjunctivitis, enteritis and ascites, but they have also been isolated from clinically healthy animals (Heuser et al., 2014, Farkas et al., 2015).

Species demarcation criteria

There is only a single species in the genus.

Member species

SpeciesVirus name(s)Exemplar isolateExemplar accession numberExemplar RefSeq numberAvailable sequenceOther isolatesOther isolate accession numbersVirus abbreviationIsolate abbreviation
Torchivirus Atortoise picornavirus43569KM873611NC_025890Complete genomeToPV

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

Derivation of names

Torchi-: from tortoise virus X (chi; Greek letter C).