Seminar by Dr. Gruninger on June 4^th from 10-11 am at  MCM258.

Application of culturomics and metagenomics to characterize the microbial pathogens associated with liver abscesses in feedlot cattle.

Gruninger RJ¹, Zaheer R¹, Chomistek N¹, King M¹, O’Hara EO¹, Ribeiro GO², Guan LL³, Zovoilis A⁴, McAllister TA¹

¹ Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada

² College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada

³ Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada

⁴ Faculty of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB, Canada

Feedlot-finishing diets in North America consist of high-concentrate rations that are formulated to provide ≤ 10% dry matter as roughage. Diets low in forage increase the incidence of metabolic and digestive disorders, and approximately 23-30% of cattle in feedlots develop liver abscesses. Severe liver abscesses are linked to reduced intake and decreased feed efficiency. In Canada, liver abscesses cost the industry approximately $61.2 million annually. The biological processes involved in the development of liver abscesses are not well understood. Metataxonomic studies have shown that while Fusobacterium necrophorum is ubiquitous among these infections, close to 50% also have high levels of unknown Bacteroidota. We present our recent efforts employing metagenomics and culturomics to examine the microbiology of liver abscesses in feedlot cattle. We obtained four high-quality MAGs, including two bacteria not previously known to be associated with liver abscess. Using a culturomics approach, pure cultures of isolates corresponding to the unknown MAGs were obtained and genomically characterized. This work provides important information on the microbial pathogens that cause the development of liver abscesses in cattle, data that will be valuable in efforts to reduce antibiotic use in livestock production and identify alternative therapeutics to in-feed antibiotics for the prevention of liver abscesses.