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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Publications at this Location » Publication #398107

Research Project: Intestinal Microbial Ecology and Non-Antibiotic Strategies to Limit Shiga Toxin-Producing Escherichia coli (STEC) and Antimicrobial Resistance Transmission in Food Animals

Location: Food Safety and Enteric Pathogens Research

Title: The impact of carbadox on the swine intestinal microbiota and intraepithelial T cell populations post-weaning

item WATKINS, HANNAH - Iowa State University
item WIARDA, JAYNE - Iowa State University
item GABLER, NICHOLAS - Iowa State University
item Loving, Crystal
item Anderson, Christopher

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/7/2021
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The interaction of intestinal intraepithelial T cells (IETs) and the microbiota is thought to play an important role in shaping gut development. We describe corresponding changes in the gut microbiome and IETs in post-weaning piglets on different diets to further characterize the relationship between the microbiota and host immunity. Thirty-two freshly weaned nursery pigs were fed a diet with or without carbadox (50 g/ton) and necropsies were performed at 14 or 28 days post-weaning (dpw). We conducted 16S rRNA gene sequencing of cecal contents and mucosal swabs of the ileum, jejunum, and cecum. Epithelial-enriched cell fractions were isolated from the same tissues, and flow cytometry was used to evaluate T cell populations and their activation states. There was no significant effect of carbadox on the microbiome of similarly aged pigs. Rather, a shift was detected between 14 and 28 dpw, and the shift was larger in pigs receiving carbadox. IET community structure significantly differed by intestinal location and time, but a treatment effect was detected only in the jejunum at 14 dpw. Considering samples across all treatments and intestinal locations, amplicon sequence variants of Lachnospiraceae and Akkermansia were positively correlated with a subset of CD27- effector-like CD2+CD8a+ gamma-delta (gd) and CD4-CD8a+CD8b+ alpha-beta (ab) IETs and negatively correlated with less terminally differentiated CD27+CD2+CD8a- gd T cells. Clostridium, Fusobacterium, and Leptotrichia had an opposite pattern of correlation with the same IETs. Findings suggest association of CD27- effector-like gd and CD8ab IETs with microbes linked to gut health, while less terminally differentiated gd IETs may be associated with bacteria commonly linked to disease. We identified disparate changes in the gut microbial and IET community structures associated with age and in-feed carbadox. Multivariate models for integrating datasets hold promise for clarifying relationships between the microbiota and IETs, which could be useful in developing strategies to improve swine production and health.