Pigs are considered a staple in the food industry, and as such veterinary scientists have long been interested in effective strategies for keeping these “wonder animals” healthy. Antibiotics have been prominent in the animal health toolbox; however there has been increasing demand by consumers for antibiotic free food (Kolotilin I et al. 2014). In addition, the World Health Organization reports that antibiotic resistance among pathogens has become a serious threat to the treatment of infectious diseases. Hence, there is a significant need for alternative strategies to treat the various pathogens that affect pigs.
Several pig-related pathogens have been identified to date, including salmonellae, Campylobacter, Trichinella spiralis, Toxoplasma gondii, Listeria monocytogenes, methicillin-resistant Staphylococcus aureus (MRSA), porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), norovirus, and African swine fever virus (ASFV). Disease outbreaks in pigs caused by these pathogens have resulted in significant economic loss to the food industry (Pappas G 2013). In fact, there is currently an ASF outbreak spreading across Europe, with 69 cases reported to date. This could cause a significant damage to the pork industry if the virus continues to spread to other European countries.
Scientists at the University of Edinburgh’s Roslin Institute are taking a novel approach to preventing disease in pigs. To address ASF, Professor Bruce Whitelaw and his research team at Roslin Institute are utilizing gene editing techniques to engineer pigs that are more resilient to ASF (Palgrave et al. 2011). The science behind their approach rests on the knowledge that endogenous African warthogs can tolerate the virus, whereas domestic pigs typically die within 2-10 days of ASFV infection. This indicates that the difference in the fatality of the disease could be due to genetic variances between the porcine species. Indeed, warthog pigs and domestic pigs differ in a key immunological protein by only three amino acids. This protein is RELA (p65), a major component of the NF-κB transcription factor, which plays a major role in immune activation. The researchers have successfully produced domestic piglets that have the same version of RELA as warthog pigs and are consequently resistant to ASFV (Lillico et al. 2013).
They have also engineered pigs that have enhanced immunity to swine flu and PRRS and plan to expand their research program to address other pig pathogens. Professor Whitelaw estimates that these genetically modified, healthier pigs could become commercially available in the next five to ten years. Other strategies to protect the health of pigs without the use of antibiotics involve the development of veterinary vaccines and other immunotherapeutic approaches (Kolotilin I et al. 2014, Murtaugh MP 2014). One unique approach involves the generation of recombinant therapeutic proteins using plant based platforms (Kolotilin I et al. 2014).
Keeping pigs healthy is important for public health, animal welfare and food supply security reasons and veterinary scientists are actively investigating ways to combat the detrimental effects of pig pathogens. Bio-Rad supports veterinary scientists as the leading supplier of veterinary research reagents and antibodies. Check out our porcine immunology range and resources.