2014-15 Rapid Ag: Analysis of Virulence-Associated Genes in Known and Novel Brachyspira Species

November 1, 2014

Principal Leader

Connie Gebhart


Veterinary Biomedical Sciences

Funding Awarded

2014 Fiscal Year: $40,000

2015 Fiscal Year: TBD

The Problem

Endemic and emerging enteric diseases alike are major constraints to the growth and productivity of the swine industry.  A novel species of Brachyspira, “B.hampsonii”  has recently emerged in Minnesota as well as in most other swine producing states and Canada. There are currently five named Brachyspira species isolated from pigs in North America and more information is needed disinguish their characteristics from eachother and ultimately develop vaccines.


Swine dysentery continues to persist globally and is re-emerging across the U.S. and Canada. If the trend continues it will hamper our trading capacity, particularly our export market. We know that the presence of swine dysentery and brachyspiral colitis in swine farms incurs huge economic loss due to poor feed conversion efficiency, decreased growth rate and mortality as well as domestic and international trade restrictions. By some estimates Brachyspira infection in a farm costs up to $10/pig in lost performance (Novartis personal communication; letter attached). Due to the emergence of Brachyspira in North America, including here in Minnesota, importing countries are now requiring screening of Brachyspira status in pigs coming out of the U.S. Lack of rapid, sensitive, inclusive, and accurate diagnostic tools are currently complicating our effort to understand and control Brachyspira infection.

The Veterinary Diagnostic Laboratory (VDL) of the University of Minnesota has been and continues to be a preferred reference laboratory for Brachyspira diagnostic testing and research trials in Minnesota, the corn belt region, other U.S. swine production farms, field veterinarians and industry collaborators (see support letters received from stakeholders). In the short term, the proposed project will directly benefit the Minnesota Swine Producers through fast and accurate delivery of services by the University of Minnesota’s VDL. The College of Veterinary Medicine’s swine enteric disease diagnostic capability will be enhanced and the swine industry will benefit from the more rapid and sensitive molecular diagnostics and targeted control strategies developed as a result of this project.


  1. Identify and sequence virulence-associated genes in known and novel highly pathogenic Brachyspira species isolated from cases of swine dysentery in North America, and compare their profiles with low-pathogenic and non-pathogenic species.

  2. Develop and validate PCR-based molecular diagnostic assays based on most frequently detected and diagnostically useful virulence-associated genes to differentiate Brachyspira species.

  3. Evaluate the usefulness of these assays for routine diagnostic application using samples collected from selected farms and from our previous controlled experimental disease reproduction studies.