By Bruce Cochrane
Research conducted at the University of Saskatchewan is helping pork producers identify and contain a new strain of brachyspira responsible for outbreaks of swine dysentery in Canada and the U.S.
Brachyspira hyodysenteriae, the pathogen responsible for swine dysentery, had been thought eradicated 25 years ago however, a few years ago swine dysentery re-emerged caused by a new strain.
In partnership with the Canadian Swine Health Board, the University of Saskatchewan has been examining that strain.
Dr. Janet Hill, an associate professor veterinary microbiology, says technology used to identify brachyspira hyodysenteriae are not effective with the new strain so researchers have gone back to some old techniques and some new.
Dr. Janet Hill-University of Saskatchewan:
For a long time, since probably sometime in the 90's swine dysentery was considered to have been essentially a non-issue, that the disease was gone.
Starting in 2008-2009 we started to see reports of swine dysentery like disease in Western Canada and it turns out around the same time in the mid-western United States.
Most recently the disease we're seeing is actually not primarily associated with brachyspira hyodysenteriae.
Instead it seems to be what we're pretty confident is actually a new species of brachyspira so kind of a cousin to the traditional hyodysenteriae and that presented a lot of challenges to us in the diagnostic lab because the tests that have been commonly used target specific organisms like hyodysenteriae so you only find what you look for and if you have something new you get negative test results which conflict with what you're seeing clinically.
Dr. Hill says going back to traditional culture methods, where the organisms are grown from clinical samples in the lab is one of the most powerful tools available, and scientists are also using molecular diagnostic techniques like PCR and DNA sequencing to help identify the organism.
She says we're gradually catching up with the diagnostics and now the focus is shifting to control.