Differential levels of cecal colonization by Salmonella Enteritidis in chickens triggers distinct immune kinome profiles

Authors: Swaggerty, Christina - Christi; Kogut, Michael - Mike; He, Louis; Genovese, Kenneth - Ken; JOHNSON, CASEY - University Of Delaware; ARSENAULT, RYAN - University Of Delaware

Submitted to: Frontiers in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/28/2017
Publication Date: 12/13/2017
Publication URL: https://handle.nal.usda.gov/10113/6472216
Citation: Swaggerty, C.L., Kogut, M.H., He, L.H., Genovese, K.J., Johnson, C., Arsenault, R.J. 2017. Differential levels of cecal colonization by Salmonella Enteritidis in chickens triggers distinct immune kinome profiles. Frontiers in Veterinary Science. 4(214):1-14. https://doi.org/10.3389/fvets.2017.00214.
DOI: https://doi.org/10.3389/fvets.2017.00214

Interpretive Summary: Salmonella is a bacterium that causes foodborne illness, and poultry products are a major source of contamination that results in these human illnesses. Despite the importance of Salmonella to human health and chickens being a known source, little is known of the response to infection inside the chicken’s gut. Using chicken-specific peptide arrays, a tool designed to determine immune responses in chicken samples, we compared the chicken gut immune response in birds with high and low infection rates of Salmonella. Baby chicks were infected with Salmonella, then pieces of gut content were collected at three different stages over the 42 day grow out: early, middle, and late. We counted the number of Salmonella bacteria and identified the birds with the highest and lowest numbers of bacteria at each time, and then we used those birds and ran our array on them. Important pathways associated with low numbers of Salmonella were focused around immune responses. Additionally, we found a small number of specific markers that were different between birds with high and low numbers of Salmonella. Identification of these specific markers which are associated with increased resistance against Salmonella provides chicken breeders with additional tools to help identify birds that are naturally more resistant to this important foodborne pathogen, potentially reducing the need for antibiotics and creating a safer food supply for the consumer.

Technical Abstract: Salmonella enterica serovar Enteritidis are facultative intracellular bacteria that cause disease in numerous species. Salmonella-related infections originating from poultry and/or poultry products are a major cause of human foodborne illness, and S. Enteritidis is the leading cause worldwide. Despite the importance of Salmonella to human health and chickens being a reservoir, little is known of the response to infection within the chicken gastrointestinal tract. Using chicken-specific kinome immune peptide arrays, we compared a detailed kinomic analysis of the chicken gut immune response in birds with high and low Salmonella loads. Four-d-old chicks were challenged with S. Enteritidis (10**5 cfu). Following this, cecal content and a section of jejunum were collected at three different time intervals: early (4-7 days post-infection [dpi]), middle (10-17 dpi), and late (24-37 dpi). Salmonella colonization was enumerated, and birds with the highest (n=4) and lowest (n=4) loads at each time were selected for kinomic analyses. Key signaling pathways associated with lower loads of Salmonella clustered around immune responses and subsequent signaling pathways include: cell surface receptor signaling pathway, positive regulation of cellular processes, defense response, innate immune response, regulation of immune response, immune system process, and regulation of signaling. Additionally, a small number of peptides were differentially phosphorylated between birds with high and low Salmonella loads including AKT3, Raf1, PLCG1, Pyk2, and SMAD2. Identification of specific proteins associated with increased resistance against S. Enteritidis provides breeders with additional biomarkers to identify birds naturally more resistant to this important foodborne pathogen, potentially reducing the need for antibiotics and creating a safer food supply for the consumer.