This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.
This week, we are sharing the summary of a publication by Dr. Fernando Leite who recently received his PhD from the University of Minnesota. The full scientific article regarding the effect of the vaccination against Lawsonia intracellularis on the shedding of Salmonella typhimurium and the host microbiome is available on open access in Nature.
Materials and Methods
A total of five treatment groups were used:
- challenged with S. Typhimurium alone,
- challenged with both S. Typhimurium and L. intracellularis,
- challenged with S. Typhimurium and vaccinated against L. intracellularis,
- challenged with both S. Typhimurium and L. intracellularis and vaccinated against L. intracellularis
- a non-infected control.
The greatest difference in shedding level between groups was found at 7 days post-infection. At this time point, the co-challenged animals from the vaccinated group shed statistically less S. Typhimurium per gram of feces than the animals from the non-vaccinated, co-challenged group. The co-challenged vaccinated group also shed significantly less S. Typhimurium than the singly infected S. Typhimurium group.
L. intracellularis vaccination did not have a significant impact on S. Typhimurium shedding when animals were singly infected with S. Typhimurium.
At 7 days post-infection, different treatment groups had significant differences in their microbiome community structure. The co-infected vaccinated group clustered apart from all other treatment groups.
These results indicate that vaccination against L. intracellularis impacts the microbiome and reduces shedding of S. Typhimurium in co-infected animals.