INVESTIGATING THE PATHOGENICITY OF PESTIVIRUSES OR PESTI-LIKE VIRUSES ISOLATED FROM RECENT SWINE EPIDEMICS

Goals / Objectives
1. Evaluate the pathogenicity of various pestiviruses or pesti-like viruses isolated from field cases of swine disease epidemics. 2. Characterize the antigenic and genetic properties of the BVDV-1 field isolate.

Project Methods
There are 3 potential lines of planned work. The first line of work, or part A, will involve evaluating the pathogenicity of the putative BVDV type 1 isolate recovered from a field case. The second and third lines of work, parts B and C, will be dependent on the pathogenicity of the BVDV field isolate and acquisition of additional field isolates. The work planned for part B will involve the antigenic and genetic characterization of the BVDV isolate. In addition, the nucleotide sequence of the 5'UTR region of the BVDV will be compared to the sequence of a BVDV isolate that was isolated in 2004 at Plum Island Animal Disease Center (PIADC). The PIADC BVDV isolate was recovered from tissues that were submitted by the CVM-UMN as part of a potential foreign animal disease investigation. If the pathogenicity studies completed in Part A indicate this BVDV isolate has unique virulence characteristics, then extensive genetic evaluation of the virus will be conducted. The work planned for part C involves in vitro and in vivo characterization of additional virus isolates and/or tissues collected from field cases during the time frame of the proposed study.

Progress 05/01/05 to 11/01/06

Outputs
Progress Report 4d Progress report. This report serves to document research conducted under a Reimbursable Agreement with the National Pork Board. Additional details of research can be found in the report for the parent CRIS 3625-32000-074-00, Emerging Viral Diseases of Swine. The objective of this agreement was to test the effect of a bovine viral diarrhea virus (BVDV) isolated from a field case of unexplained high mortality in finishing-age swine. This BVDV isolate was typed and characterized by sequencing, monoclonal antibody binding, and growth in tissue culture cells derived from different species. In addition, experimental BVDV infection had minimal to no clinical effect on pigs. Additional studies are planned to test for any synergistic effect between the BVDV and a unique bacteria, Haemophilus parasuis serotype 13, that was also isolated from the field case.

Impacts
(N/A)

Publications

Progress 10/01/04 to 09/30/05

Outputs
4d Progress report. This report serves to document research conducted under a Reimbursable Cooperative Agreement between ARS and National Pork Board that began on May 1, 2005. Additional details of research can be found in the report for the parent CRIS 3625-32000-074-00D, Emerging Viral Diseases of Swine. The objective of this agreement is to determine the ability of a unique swine virus to cause disease in pigs. This virus was isolated from a field case that had high mortality in affected pigs and it is related to a commonly found cattle virus. The approach will involve experimental inoculation of pigs with this virus isolate followed by observation for any signs of disease related to the virus inoculation. If this virus isolate causes disease, then additional animal experiments will be conducted to determine the best tissues to collect that would aid in the efficient diagnosis of this virus infection and field studies may be initiated to determine the true incidence and impact of this virus to the swine industry.

Impacts
(N/A)

Publications