Equine arteritis virus: a new isolate from the presumable first carrier stallion in Argentina and its genetic relationships among the four reported unique Argentinean strains.

The research article covered the identification of a new strain of the Equine Arteritis Virus (EAV) in Argentina, potentially the original source of EAV infection in the country, extracted from a stallion’s testicle.

Research Background

• The researchers focused on the Equine arteritis virus (EAV), a virus that can cause disease in horses.
• The virus was isolated from a testicle from the first suspected stallion host in Argentina, signaling its genetic journey in the country.
• This isolated virus was named LT-LP-ARG and was confirmed as EAV through GP5-specific PCR and indirect immunofluorescence assays.

Methodology

• To confirm the identity of the virus, a GP5-specific PCR (a form of Polymerase Chain Reaction, a common DNA/RNA investigation) and indirect immunofluorescence assays (tests that use antibodies to identify specific substances) were performed.
• The PCR product was then sequenced, a process to determine its exact genetic composition.

Findings

• Upon phylogenetic analysis, which studies the evolutionary relationships between different species, or in this case, strains, the researchers found that LT-LP-ARG forms a monophyletic group with other EAV strains previously isolated in their laboratory (the LP02 group).
• A monophyletic group refers to a set of organisms or species that shares a single common ancestor. Therefore, it suggests these different strains have comparable genetic composition.
• Interestingly, all Argentinean EAV strains found so far belong to a polyphyletic group. In contrast to monophyletic, polyphyletic groups comprise organisms or species that are derived from two or more different ancestors, indicating higher genetic diversity.

Consequence of the findings

• The researchers propose that the isolated LT-LP-ARG virus strain may have been the origin, or ‘patient zero’, of all EAV infections in Argentina. This suggestion is based on its comparative genetic makeup.
• Further investigations will be required to confirm this hypothesis

Overall, this study offered important insights into the EAV’s genetic diversity in Argentina, potentially identifying the original virus strain in the country. It ultimately provides a foundation for further investigations into its transmission dynamics and informs future vaccinations and control measures.