$3M grant to shed light on porcine virus

Veterinarians and farmers are on their way to better understanding the life cycle of a prevalent porcine virus, thanks to new funding. The affliction, which spreads rapidly within barns and between farms, costs the U.S. swine industry more than $560 million each year.

Researchers out of University of Minnesota College of Veterinary Medicine and collaborators at the University of Edinburghs Roslin Institute have received a $3-million grant to explore the evolution and proliferation of porcine reproductive and respiratory syndrome virus (PRRS). Researchers hope the study will facilitate a better understanding of how the virus spreads, allowing farmers and scientists to anticipate a herds susceptibility to different strains of it and customize mitigation efforts accordingly.

Studying PRRS viruss evolution will help us better understand and, hopefully, control it, but it will also help us understand the evolution and drivers of genetic diversity in viruses in humans and other animals, says Dr. Kim VanderWaal, an assistant professor in the universitys department of Veterinary Population Medicine and the projects principal investigator.



Porcine epidemic diarrhea virus (PEDV) can infect pigs of all ages. At present, Epidemic diarrhea (PED) is the main cause of diarrhea and death in piglets, which seriously threatens the economic benefits of pig farms.

Lidan Sun and Ligong Chen with their team made a research on the PEDV, aiming to establish an indirect ELISA method for detecting IgA antibody against PEDV and provide a technological means to PEDV infection detection and immune effect evaluation. Using this method, antigen coating concentration, blocking and dilution buffer, optimal dilutions of test serum and enzyme-labeled antibody were determined. Furthermore, the specificity, intra- and inter-batch repeatability tests of the ELISA were examined, the coincidence rate were measured between the ELISA and the existing ELISA kit, and the correlation between the specific IgA and the neutralizing antibodies in serum was analyzed.

The results showed that the optimal antigen coating concentration of the ELISA was 1μg/mL, the blocking and dilution buffers were PBS containing 5% calf serum and 0.05% Tween-20, and the working concentrations of tested serum and enzyme-labeled antibody were 1:40 and 1:1500, respectively.

The method could be used to detect the PEDV-specific antibodies without cross reactions with those against PRRS virus, classical swine fever virus, pseudorabies virus, and porcine circovirus type 2. The coefficients of variation (CV) of intra- and inter-batch repetitive tests of the ELISA were less than 10%. The coincidence rate was 94.8% when the same serum samples were detected using the ELISA and existing ELISA kit for detecting PEDV antibody. The level of specific IgA antibody was positively correlated with that of the neutralizing antibody in serum (r=0.69, p<0.001).

This method can not only be used for PEDV infection detection and epidemiological investigation, but also can monitor the immune status of pregnant sows and predict the effect of piglets on maternal passive immune protection.

Read the full paper at the journal of Probe - Animal Science: http://probe.usp-pl.com/index.php/PAS/article/view/1314