In early 2014, a Minnesota sow farm with a solid vaccination history suffered a severe porcine reproductive and respiratory syndrome (PRRS) outbreak with unusually high morbidity and mortality in piglets and sows, as well as anorexia and secondary bacterial infections in nursery pigs. Due to the unusual clinical severity in a PRRS-immune herd, genetic characteristics of the virus were examined to determine if a new PRRSV genotype had emerged. Phylogenetic analysis indicated that the virulent strain (PRRSV2/USA/Minnesota414/2014) was related to virulent strains circulating in the mid-western United States in recent years, and that the nonstructural protein 2 (nsp2) gene of MN414 contained an insertion-deletion pattern typical of existing type 2 virulent strains. We conclude that the MN414 isolate is a recently evolved member of the virulent lineage 1 family of type 2 PRRSV.
Bibliographical noteFunding Information:
We thank Wanxue Meng from the Department of Geography, University of Minnesota, for her cartographical support, and Mark Schwartz from Cottonwood County, MN, for sharing data and support of the study. This project was funded by the University of Minnesota Veterinary Diagnostic Laboratory. Xiong Wang is supported by a MNDrive Global Food Ventures Fellowship from the state of Minnesota.
© 2015 Elsevier B.V..
- Full genome
- Type 2 PRRSV
- Virulent strain