TlyA Protein Key in Determining Severity of Brachyspira Associated Diarrhea

Researchers with the Western College of Veterinary Medicine have identified the TlyA protein as one of the factors that plays a role in the severity of Brachyspira associated diarrhea in swine. Brachyspira is a common bacteria found in several species, certain strains of which can cause symptoms in pigs ranging from mild diarrhea to severe mucosal hemorrhagic dysentery. Researchers with Western College of Veterinary Medicine are exploring the role of certain proteins that are part of Brachyspira hampsonii.

Dr. Matt Loewen, an Associate Professor in Veterinary Medical Biosciences with the Western College of Veterinary Medicine, explains some of the variability in severity of symptoms can be attributed to the environment, such as the barn or the diet, but other differences are due to species differences.

Clip-Dr. Matt Loewen-Western College of Veterinary Medicine:

When we look at those species differences, we can look at them and say there are specific proteins being expressed in one species of bacteria but not in another species of bacteria. We know that there are specific proteins that are expressed in more virulence and then they're not necessarily expressed in less virulence.

We've specifically narrowed down different proteins that could be important virulence factors to a couple of proteins that are involved in hemolysis and this one protein that we've been spending a lot of time looking at is TlyA, which looks like it could be a hemolysin. We've basically got to the point that we can say that it is a hemolysin. It does have that activity.

We also know that, looking at other less pathogenic Brachyspira species, that they have mutations in it that would potentially disrupt its function. We've made those mutations and demonstrated that the protein does not function as a hemolysin and missing a few other functions if those mutations are there.