Viruses:
Highly pathogenic PRV JS-2012 variant strain (Tong et al., 2015) was obtained from Shanghai Veterinary Research Institute, Shanghai, China. The classical PRV strain Bristol (classical strain), Shope, Becker, and Bartha strains were available at the National Centre for Foreign Animal Diseases (NCFAD)-Winnipeg. All these viruses were propagated and titrated in PK-15 cells. The PRV modified live vaccine AUSKIPRA - GN (PRV Bartha-K61 strain) was purchased from Laboratorios HIPRA S.A. in Spain and PR-VAC PLUS (PRV Bucharest strain) was kindly provided by Zoetis Inc. in Lincoln, NE, USA. PRV genomic DNA was extracted from tissue culture amplified virus, PRV positive clinical samples, or from vaccines reconstituted in PBS. Cross reactivity (analytical specificity or exclusivity) of the PCR with other swine viruses was tested with a genomic panel comprised of swine viruses extracted from cell culture amplified African and classical swine fever viruses and foot and mouth disease virus (FMDV); clinical samples positive for porcine respiratory and reproductive syndrome virus (PRRSV), porcine epidemic diarrhea virus (PEDV), and porcine circovirus 2 (PCV2); and herpesviruses originating in bovine, elk , caprine, Rangifer , and an unknown cervid . PRV pUC57 plasmid (545 ng/µL) was purchased from Genscript.