Date Full Report Received


Date Abstract Report Received



Primary Investigator: ,
Co-Investigators: Dr. Karen M. Harmon

It is widely accepted that PRRSV can be monitored in swine populations more conveniently, efficiently, and cheaply using oral fluid specimens as compared to surveillance based on testing
individual pig serum samples. Oral fluids are a convenient sample to collect, but are often heavily contaminated with feed, feces, and inorganic environmental debris. Attempts to “clean
up” samples by centrifugation or filtration have not been effective. Alternatively, we have identified a coagulant formulation among several evaluated that is compatible (do not interfere/inhibit test performance) with antibody and PCR-based testing. Preliminary results indicate that this formulation could also assist in:
1. Cleaning-up: removing particulates from oral fluid samples (Figure 2).
2. Sample handling: improving the “handling characteristics” (pipetting) of the sample.
3. Antibody detection:
♦  Reducing ELISA non-specific reactions (background).
♦  Improve or retain the PRRS antibody ELISA sample-to-positive (S/P) response of antibody-positive samples compared to non-treated oral fluid samples → do not affect antibody-based tests performance.
4. Nucleic acid (RNA) detection:
♦  Selected coagulant is “PCR friendly” and did not cause PCR-inhibition at its optimal concentration.
♦  Selected active formula precipitated out of the matrix, suggesting the possibility of concentration of PCR targets by precipitation, thereby improving the sensitivity of PRRSV RTPCR assays.
Current research is investigating the possibility of improving oral fluid PCR diagnostics by concentrating targets in the oral fluid precipitate.
5. Field application: lyophilized format is ready for use in the field under ambient conditions → do not required.
♦  The ultimate goal of this research line is to provide with more effective, efficient, inexpensive methods of surveillance for use in the prevention, control, and/or elimination of PRRSV and other economically-significant infectious agents.