Experts study bacteria to create vaccine

The old saying, “you need to learn to walk before you run,” is apt in vaccine research.


Researchers hope to discover how a bacteria interacts with the cells of pigs’ intestines before trying to develop a vaccine to halt the disease it causes, which is still unnamed.


“We start with an understanding of what is happening at the intestinal cell level,” said Dr. John Harding of the University of Saskatchewan’s Western College of Veterinary Medicine.


A team of researchers, led by Harding, is taking a new tack to understanding and controlling brachyspira hampsonii, which causes diarrhea in grower and finisher pigs. 


A vaccine is traditionally made either by growing the bacteria and feeding it live to the animal or growing the bacteria, killing it and injecting it into animals to create antibodies against the disease.


However, this disease’s relatives have proven resistant to traditional vaccine development. 


Harding’s team is using a three-year research grant to start at the cellular level to find out how the disease causes inflammation in the large intestine and damages cells. Once the researchers find out how the disease works, they can attempt to develop blocking mechanisms.


The disease is a new species of bacteria that has been around for a long time. 


It was originally discovered in the 1970s and was widespread for many years in pig barns. It disappeared in the 1990s as older contaminated barns were taken out of service and new larger barns were built that had yet to be contaminated.


The disease caused by the bacteria began to appear again in the early 2000s. 


It can cause death in severe cases, although pigs recover from the diarrhea. However, it does cause major economic losses because of in-creased mortality and reduced growth rates and feed efficiencies.


The disease has been seen in pig barns only in Alberta and Saskatchewan. 


Testing and reporting isn’t mandatory so officials don’t know exactly how prevalent it is.


Harding said they are using a multidisciplinary approach to understand the disease with experts in physiology, microbiology, pathology and swine medicine. He hopes this will help determine the interactions between the pathogens and animals’ intestinal cells.


Harding said it is too early to say if the research will lead to a cure, but it is leading to a “promising interpretation of what is going on in the intestine.”


The goal is to understand the mechanism and then propose strategies on how to develop a vaccine.


He hopes to have enough answers by the end of the three-year grant that will allow him to apply for a grant to develop a vaccine.


“We have to start somewhere. You can’t discover these things overnight,” he said.