Effects of synbiotic supplementation as an antibiotic growth promoter replacement on cecal Campylobacter jejuni load in broilers challenged with C. jejuni

Authors: CASON, EMILY - University Of Georgia; AL HAKEEM, WALID GHAZI - University Of Georgia; ADAMS, DANIEL - University Of Georgia; Shanmugasundaram, Revathi; SELVARAJ, RAMESH - University Of Georgia

Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/6/2022
Publication Date: 11/9/2022
Citation: Cason, E.E., Al Hakeem, W., Adams, D., Shanmugasundaram, R., Selvaraj, R. 2022. Effects of synbiotic supplementation as an antibiotic growth promoter replacement on cecal Campylobacter jejuni load in broilers challenged with C. jejuni. Journal of Applied Poultry Research. 32(2):100315. https://doi.org/10.1016/j.japr.2022.100315.
DOI: https://doi.org/10.1016/j.japr.2022.100315

Interpretive Summary: Campylobacteriosis is one of the most reported bacterial food-borne illnesses in U.S each year. Chickens are a natural host for Campylobacter jejuni and are the primary source of human infection. Chickens are persistent carriers of C. jejuni and do not show any clinical symptoms, or decreased production performance. However, higher transmission rates and fecal shedding contaminate the carcass at the processing plant. This ultimately increases the food safety concern. Antibiotic growth promoters increase antibiotic resistance in chickens. Hence, synbiotics could be a potential alternative to antibiotics in poultry production. Hence, this study evaluated the effects of a synbiotic supplementation in broilers challenged with C. jejuni. Synbiotic supplementation decreases C. jejuni loads in broilers and beneficially modulates the immune response to C. jejuni challenge, compared to antibiotic control groups. Hence, synbiotics can be applied to replace antibiotic growth promoters during C. jejuni infection in poultry.

Technical Abstract: Synbiotic supplementation alters gut microbiota via competitive exclusion, improve production performance, decrease cecal Campylobacter jejuni load and colonization, and improve immunological responses and is an alternative to antibiotic growth promoters in poultry production. This study aimed to determine effects of synbiotic supplementation as an antibiotic replacement C. jejuni challenged broilers. 336-one- day-old broiler chicks were distributed into four treatment groups: Control, Synbiotic, Antibiotic + Challenge, and Synbiotic + Challenge, with six replicate pens per treatment. Antibiotic and synbiotic were supplemented in feed 20 mg/kg and 20 g/1000 birds/day, respectively. At 21 days of age, birds were orally inoculated with PBS or 1 X 108 CFU/bird C. jejuni. Feed intake and body weight were measured on weekly basis. On 3, 7, and 14 dpi, gut permeability, anti-C. jejuni IgA bile concentration, C. jejuni cecal content, ileal tissue, and liver load, splenocyte adherent mononuclear cell nitric oxide production, and cecal tonsil CD4+:CD8+ and CD4+:CD25+, cytokines mRNA transcription, and tight junction protein expression were quantified and statistically analyzed. There were no significant differences in BWG, FCR, intestinal integrity, or bile anti-C. jejuni IgA concentration between treatments. 7 and 14 dpi, Synbiotic + Challenge birds had a significantly lower (P < 0.05) cecal C. jejuni load than Antibiotic + Challenge birds. 3 dpi, cecal tonsil CD4+:CD25+ was significantly higher (P < 0.05) in the Synbiotic + Challenge than Synbiotic group. 7 dpi, cecal tonsil CD4+:CD8+ was significantly higher (P < 0.05) in the Challenge groups than in the Synbiotic and Control groups. 0 dpi, tight junction proteins were upregulated significantly (P < 0.05) in Synbiotic and Synbiotic + Challenge treatments. 0, 3, and 7 dpi, T-cell differentiation gene, pro-, and anti-inflammatory cytokine expression were all upregulated or downregulated? significantly by synbiotic supplementation and challenge. We concluded synbiotic supplementation decreases C. jejuni loads in broilers and beneficially immunomodulates in response to challenge, compared to antibiotic supplementation, and that synbiotics can be applied to replace antibiotic growth promoter usage during poultry C. jejuni infection.