Molecular characterization of a new PToV strain. Evolutionary implications

Area of Science:

• Veterinary Virology
• Molecular Biology
• Immunology

Background:

• Toroviruses are emergent viruses within the Nidovirales order, causing enteric diseases in animals and humans.
• Only five variants of porcine torovirus (PToV) have been identified to date.
• Porcine toroviruses remain largely understudied despite their potential impact.

Purpose of the Study:

• To identify and characterize a new strain of porcine torovirus (PToV).
• To develop and validate an enzyme-linked immunosorbent assay (ELISA) for detecting antibodies against PToV.
• To assess the prevalence of PToV antibodies in Spanish swine populations.

Main Methods:

• RT-PCR was used to detect and identify a novel PToV strain (PToV-BRES) in swine fecal samples.
• Genes for nucleocapsid (N), hemagglutinin-esterase (HE), and membrane (M) proteins were amplified and sequenced.
• The PToV-BRES nucleocapsid protein was expressed and purified for use in an ELISA.

Main Results:

• A new PToV strain, PToV-BRES, was identified and partially characterized from a swine sample in Italy.
• Sequence analysis, particularly of the HE gene, placed PToV-BRES within a distinct phylogenetic lineage.
• The developed ELISA demonstrated high antibody prevalence against PToV in adult pigs and piglets across three Spanish farms.

Conclusions:

• PToV-BRES represents a novel strain of porcine torovirus.
• The high antibody prevalence suggests PToV may be endemic in the Spanish porcine population.
• The developed ELISA is a valuable tool for future epidemiological studies on toroviruses.