PSIII-18 Assessment of Salmonella Dublin infection of intestinal porcine epithelial cells (IPEC) in response to Zinc Oxide and a Yeast Mannan Rich Fraction

Abstract

Abstract Salmonella species are associated with post-weaning diarrhea, which results in poor weight gain, potential death, and economic cost. A yeast mannan rich fraction (MRF) was assessed alongside the industry standard treatment Zinc Oxide (ZO) in vitro to determine its impact on Salmonella Dublin infection of a pig intestinal cell line (IPEC). IPEC cells were exposed to MRF or ZO in the presence of S. Dublin (1x108/mL). IPEC cell RNA was isolated and cDNA synthesized. Gene expression for IL-1β, TNFα, IL-8 and cellular tight Junction genes Occludin, Claudin3 and Tight junction protein1 (TJP1) were assessed by qPCR. S. Dublin adhesion to IPEC cells (500:1) assessed in the presence or absence of either ZO or MRF for 1 hour at 37°C. IPEC cells with attached S. Dublin were lysed, diluted, plated and incubated overnight and enumeration. Three biological replicates were performed for all experiments and statistical analysis determined by One-way ANOVA. Proinflammatory gene TNFα was significantly reduced (P ≤ 0.001) following S. Dublin infection and treatment with MRF compared with ZO. IL-1β demonstrated no change between treatments although IL-8 gene expression was significantly reduced in both ZO (P≤0.01) and MRF (P ≤ 0.05) treated cells over the control. Significantly higher expression of Occludin (P ≤ 0.01), Claudin3 (P ≤ 0.001) and TJP1 (P ≤ 0.05) was observed in IPEC cells exposed to S. Dublin in the presence of MRF compared to ZO. Adhesion of S. Dublin to IPEC cells was significantly reduced in response to MRF addition compared to ZO treated cells (P ≤ 0.001) and the control cells (P ≤ 0.05). ZO treated cell demonstrated no improvement over the control cell levels of bacterial attachment. Both on a physical and molecular level bacterial infection of intestinal cells was more significantly impaired by MRF addition. With the ban on ZO, yeast MRF may prove to be a suitable alternative to support gut health in piglets.