|Landgraf, John - USDA, APHIS, NVSL|
|Frey, Merwin - USDA, APHIS, NVSL|
Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 30, 1997
Publication Date: N/A
Interpretive Summary: Porcine reproductive and respiratory syndrome (PRRS) virus is a pathogen of pigs causing one of the most costly diseases currently faced by the swine industry worldwide. Since severe outbreaks of the disease can occur in vaccinated herds, the origin of PRRSV from diagnostic samples is often in doubt. We have developed a DNA-based test that clearly differentiates the vaccine strain RespPRRS from field strains of PRRSV. The test is accurate and requires only 2 days to report results after the virus is isolated. This differential test will be a valuable tool in PRRS epidemiological studies and will benefit pork producers, veterinary practitioners, and diagnosticians in controlling this disease.
Technical Abstract: The source of porcine reproductive and respiratory syndrome virus (PRRSV) isolated from diagnostic samples is often in doubt so we have investigated the suitability of restriction fragment length polymorphism (RFLP) analysis for differentiating vaccine strain RespPRRS/Repro (registered trademark) from field strains of PRRSV. Based on open reading frame 5 (ORF 5) nucleotide sequence data of RespPRRS/Repro vaccine virus, it's parent strain VR-2332 and 22 other strains of PRRSV included in this study, we hypothesize that 3 restriction enzyme gel patterns characterize the RespPRRS/Repro vaccine virus and the parent strain genotype. The combined 3 RFLP patterns differentiate the vaccine and parent virus from other PRRSV strains. This test will be a valuable tool in PRRS epidemiological studies and will be useful in identifying individual strains in cases of multi-strain PRRSV infections.