Surprising Discoveries Could Lead to New Antiviral Drugs to Combat PRRS

A surprising discovery related to the interactions between Porcine Reproductive and Respiratory Syndrome virus and other infectious agents may lead to new antiviral drugs to fight PRRS. PRRS virus causes respiratory problems in pigs of all ages, reproductive problems in sows and costs the Canadian swine sector about 150 million dollars per year.

With funding from Swine Innovation Porc Researchers with the University of Montreal have been evaluating the interactions between PRRS and other disease-causing pathogens.Dr. Carl Gagnon, a professor with the University of Montreal and a member of the swine and poultry infectious disease research center, says the initial objective was to understand how PRRS and other pathogens interact.

Quote-Dr. Carl Gagnon-University of Montreal:

In one of the studies that we've done we were looking at a bacteria that we call Actinobacillus pleuropneumoniae.It's a highly pathogenic bacteria that rarely causes health issues in pigs but, when it's there and it's a highly pathogenic strain, then it could be very very deadly to pigs.

If we had PRRS virus and this specific bacteria, what is the mechanism involved and can PRRS virus facilitate Actinobacillus pleuropneumoniae colonization of the animal or facilitate infection by the bacteria?Completely surprisingly, when the bacteria was present during PRRS virus co-infection, we have an inhibition of PRRS virus replication so the presence of the bacteria was blocking the infection of PRRS viruses.

So, we started to investigate this phenomenon to try to understand what was happening and we realised that the bacteria was secreting at least one or several molecules that could actually have an antiviral effect against the virus.The financial support from SIP is to try to characterise the molecules, identify those bacterial molecules to hopefully develop an antiviral against PRRS viruses.

Dr. Gagnon says, by characterising the mechanism of action of those molecules, it's hoped we can find others that can be used to develop cost effective interventions for PRRS.