Location: Virus and Prion ResearchTitle: Chinese and Vietnamese strains of HP-PRRSV cause different pathogenic outcomes in United States high health swine Author
|Kehrli Jr, Marcus|
Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2013
Publication Date: 11/1/2013
Publication URL: http://handle.nal.usda.gov/10113/58281
Citation: Guo, B., Lager, K.M., Schlink, S.N., Kehrli, Jr., M.E., Brockmeier, S.L., Miller, L.C., Swensen, S.L., Faaberg, K.S. 2013. Chinese and Vietnamese strains of HP-PRRSV cause different pathogenic outcomes in United States high health swine. Virology. 446(1-2):238-250. Interpretive Summary: Porcine reproductive and respiratory syndrom virus (PRRSV) is the foremost disease of swine in the United States. In this report, an infectious clone of a Vietnamese strain of highly pathogenic PRRSV (HP-PRRSV), prevalent in Asia but foreign to the United States, was prepared and compared to a Chinese strain of HP-PRRSV as well as the North American Type 2 prototype virus VR-2332. Both HP-PRRSV strains were found to be highly pathogenic to United States commercial swine, but differed in the extent of pathogenesis seen. The highly pathogenic (HP) virus from China was found to replicate to a higher level and caused more severe disease than the HP-PRRSV strain from Vietnam, but both were much more pathogenic than VR-2332. The results confirm that the Asian HP-PRRSV strains are an economic threat to the US pork industry.
Technical Abstract: An infectious clone of a highly pathogenic PRRSV strain from Vietnam (rSRV07) was prepared, analyzed and compared to Chinese highly pathogenic PRRSV rJXwn06 and US Type 2 prototype VR-2332 in order to examine the effects of virus phenotype and genotype on growth in MARC-145 cells, as well as the importance of challenge dose and viral strain on 4-week old swine pathogenicity and host response. We found that the two HP-PRRSV strains could be distinguished from each other by several viral properties. Furthermore, a 9-plex cytokine panel revealed that the cytokine responses varied between the different strains of PRRSV, the tissue examined and the input dose of virus.