Prof. Tanja Opriessnig completed her veterinary degree at the University of Veterinary Medicine in Vienna, Austria in 2000.

In 2002, she received her advanced degree in Veterinary Science from the same University.

From 2002 to 2006, Prof. Opriessnig worked as a postdoctoral researcher at Iowa State University and she completed a Ph.D. in Veterinary Pathology.

From 2006 to 2013, she worked as Veterinary Diagnostic Pathologist at the Assistant, Associate or Full Professor rank at the Veterinary Diagnostic Laboratory at Iowa State University.

Since 2013 Prof. Opriessnig had a joint appointment with the Roslin Institute, University of Edinburgh and the Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University.

Since 2022 she works at the Moredun Research Institute. Her current research focus is on pathogenesis, control, and diagnosis of infectious pathogens in pigs with emphasis on porcine circovirus type 2, porcine reproductive and respiratory syndrome virus, Erysipelothrix rhusiopathiae, Lawsonia intracellularis, porcine parvovirus, porcine astrovirus, porcine epidemic diarrhea virus, and swine hepatitis E virus.

Since 2002, Prof. Opriessnig published >250 peer-reviewed manuscripts in various journals of virology, microbiology and veterinary relevance.


Institute 1:
Group Leader in Terrestrial Livestock Viruses, Vaccines and Diagnostics Department, Moredun Research Institute, Penicuik, Scotland, United Kingdom

Institute 2:
Professor, Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, Iowa, United States


Austria 🇦🇹  


Impact of probiotics on Lawsonia intracellularis infection and the gut microbiome

The causative agent of ileitis, Lawsonia intracellularis, is commonly associated with diarrhea and reduced weight gain in growing pigs. Previously we assessed the effect of in-feed probiotics on L. intracellularis infection dynamics was evaluated. We determined that there was a delay in onset of L. intracellularis shedding in groups supplemented with the chosen probiotics, which was reflected in less severe macroscopic and microscopic lesions, reduced intralesional L. intracellularis antigen levels and a lower area under the curve for bacterial shedding. Under the study conditions, two of the probiotics tested suppressed L. intracellularis infection. The obtained findings show the potential of probiotics in achieving antibiotic-free control of L. intracellularis. Subsequently the bacterial microbiota of the ileum of these pigs was characterized with 16S rRNA gene sequencing and was subsequently analysed with bioinformatics tools.
The greatest microbial richness was observed in the probiotic treated group. Probiotic supplementation of a base feed ration increased ileum microbiota diversity leading to a mitigation of the effects of a pathogenic L. intracellularis challenge.