Evaluating the presence of humoral immune response to Campylobacter colonization in broiler chickens

Authors: KALAPALA, TANMAIE - University Of Arkansas; ASSUMPCAO, ANNA - University Of Arkansas; KUMAR-PHILLIPS, GEETHA - University Of Arkansas; OBE, TOMI - University Of Arkansas; Jesudhasan, Palmy; Donoghue, Ann; Arsi, Komala

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/2024
Publication Date: 1/28/2025
Citation: Kalapala, T., Assumpcao, A., Kumar-Phillips, G., Obe, T., Jesudhasan, P., Donoghue, A.M., Arsi, K. 2025. Evaluating the presence of humoral immune response to Campylobacter colonization in broiler chickens. Abstract. 2025 International Poultry Production Expo, January 28-30, 2025.

Interpretive Summary: Campylobacter jejuni (Cj) is one of the major foodborne pathogens cause human foodborne illnesses. Poultry meat and meat products are main source for the illnesses, however, Cj is normal flora in poultry. Current strategies to control Cj in poultry is not effective. Understanding the humoral immune response to Cj colonization in broiler chickens would enable us to develop effective vaccines, so we challenged broiler chickens with Cj on day 7. We had eight different groups and chicks in seven groups were challenged with wild Cj strains K1, K5, K6, S1, S3, S4, or 6-strains cocktail and the eighth group was negative control (not exposed to Cj). On day 14, birds were euthanized, samples were collected for microbiological and immunological analyses. Microbiology analysis confirmed the presence of Cj in all the groups except the negative control. Immunological analysis showed high titers of anti-Cj IgY in the yolk sac and blood serum, and anti-Cj IgA in the cecal mucous of day-of-hatch birds, strongly suggesting maternal immunity transference against Cj. Additionally, IgM levels increased from the day-of-hatch to day 14 in all the groups, with a significant increase in all the K strains and the cocktail group, suggesting the development of an anti-Cj humoral immune response. In conclusion, our study found that Cj induces a humoral immune response appropriate for breeders to transfer immunity vertically, providing the basis for further Cj vaccine studies.

Technical Abstract: Campylobacter jejuni (Cj) is a leading cause of foodborne illness, globally, often linked to consumption of poultry. Unfortunately, current strategies including vaccines to control Cj in poultry have had limited success. In this regard, understanding the humoral immune response to Cj colonization in broiler chickens is essential for developing effective vaccines. Ten day-of-hatch chickens were used at the beginning of the study. Cecal and yolk sac contents along with blood were used to assess maternal immunity and the cecal contents were also assessed for the presence of Campylobacter. For the study, 56 day-of-hatch chicks were randomly divided into eight treatment groups (n=7 birds/ treatment), including a negative control (NC), and allocated to their respective pens. On day 7, birds were orally gavaged with 0.25 mL of vehicle (NC) or wild strains K1, K5, K6, S1, S3, S4, or 6-strains cocktail for respective groups ('1×107 CFU/mL). On day 14, birds were euthanized, samples were collected for microbiological (cecal contents) and immunological analyses (blood and cecal contents). Cecal contents were diluted and plated on Campylobacter line agar plates to enumerate Cj. Blood, yolk sac, and cecal contents were processed to extract serum and mucus. Indirect ELISA was performed to determine anti-Cj IgY, IgM, and IgA levels. Campylobacter counts were log10 transformed for statistical analysis. All the data were analyzed using one-way ANOVA followed by Dunnett’s post hoc comparison, using GraphPad Prism 10 Software, and a P-value<0.05 was considered significant. Microbiology analysis confirmed the presence of Cj in all the groups except the negative control. Immunological analysis showed high titers of anti-Cj IgY in the yolk sac and blood serum, and anti-Cj IgA in the cecal mucous of day-of-hatch birds, strongly suggesting maternal immunity transference against Cj. Additionally, IgM levels increased from the day-of-hatch to day 14 in all the groups, with a significant increase in all the K strains and the cocktail group, suggesting the development of an anti-Cj humoral immune response. In conclusion, our study found that Cj induces a humoral immune response appropriate for breeders to transfer immunity vertically, providing the basis for further Cj vaccine studies.