PRRS – Swine in Minnesota

PRRSv ORF5 difference from VR2332 by herd type

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, the MSHMP team assessed differences in ORF5 sequences compared to VR2332 based on the type of farm, the sequence was collected at.

Key points

Breeding herd sequences differ 8%-16% while in other herd types they differ 1%-15% from VR2332 at the ORF5 level.
The larger nucleotide identity (%) range compared to VR2332 in growing pigs suggests a higher viral diversity within this group.

Use of Whole Genome Sequencing during a PRRSv outbreak investigation

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

We hope our US readers had a great Thanksgiving surrounded by loved ones. We are grateful that all of you keep reading us week after week and we hope we can continue providing you with valuable content for a long time!

This week, Drs. Sunil Mor and Albert Rovira from the University of Minnesota Veterinary Diagnostic Laboratory explain how we can use whole genome sequencing during a PRRS outbreak investigation.

Key Points

Viral recombination is documented in PRRSv
Whole Genome Sequencing can provide the detailed information to better understand recombination and PRRSv dynamics

Can 2 strains of PRRSv be highly homologous but have distinct virulence?

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

Key points

Two novel HP-PRRSV variants (XJ17-5 and JSTZ1712-12) that have the new genetic feature of 150-amino-acid deletion in nsp2 were identified.
Even though XJ17-5 and JSTZ1712-12 isolates share high genomic homology, they had distinct pathogenicity for piglets.
Fragment comparisons identified 34 amino acid differences between the two isolates which might be related to distinct virulence.

PRRSV 1-7-4 ORF5 diversity over time

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, the MSHMP team is looking at 16 years of genetic diversity of ORF-5 from the PRRS virus sequences submitted by the MSHMP participants

Key Points

PRRSV ORF5 sequence monitoring over time contributes to the understanding of pathogen evolution.
Range of PRRSV 1-7-4 percent divergence has decreased over the last 16 years between 2003 and 2019, which is consistent with lineage turnover previously described.
PRRSV 1-7-4 can belong to a specific lineage or sublineage, 1A being the most common currently.

Focusing on the grow/finish stages of production to better control PRRS, the new challenge of the swine industry?

Should we redirect our research efforts to focus on PRRS prevention and control in growing and finishing pigs? This was the call for action made by Dr. Montse Torremorell, Associate Professor at the University of Minnesota when she opened the special session “Grow/finish phase of production: What are we learning and implications for making progress on PRRS control.” sponsored by Boehringer Ingelheim during the North American PRRS Symposium this past weekend in Chicago. Torremorell argued that if the swine industry wants to advance regional PRRS control, more emphasis needs to put on preventing and controlling PRRS in growing pigs.