Porcine reproductive and respiratory syndrome virus (PRRSV) is responsible for a disease characterized by reproductive and respiratory complications in pigs. PRRSV exhibits substantial genetic diversity throughout the genome, so it is important to utilize whole-genome sequencing to accurately depict the full variation present. In this study, a strain of PRRSV affecting a Midwest research farm was sequenced using the Oxford Nanopore platform and a cost-effective Flongle flow cell. The strain identified was determined to belong to the 1-4-4 L1C.5 lineage of PRRSV-2 based on current open reading frame 5 (ORF5) classification, having 98% nucleotide identity at genome level when compared with other available PRRSV strains. Phylogenetic analyses demonstrated that strains classified under an ORF5-based lineage system could cluster outside of their lineage when whole-genome sequences were compared, confirming the importance of whole-genome sequencing for PRRSV classification.

Read the full article in the Journal of Animal Science.