Location: Toxicology & Mycotoxin Research
Title: Immune responses, gut permeability, and cecal Campylobacter jejuni loads in an experimental C. jejuni challenge model in broilersAuthor
CASON, EMILY - University Of Georgia | |
ADAMS, DANIEL - University Of Georgia | |
AL HAKEEM, WALID - University Of Georgia | |
Shanmugasundaram, Revathi | |
SELVARAJ, RAMESH - University Of Georgia |
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 6/21/2022 Publication Date: N/A Citation: N/A Interpretive Summary: N/A Technical Abstract: Campylobacter jejuni is a food borne pathogen that colonizes the ceca and disseminates from the gut to the internal organs by compromising gut integrity. This study aimed to characterize the host immune response of broilers and broiler cecal C. jejuni loads to establish an experimental infection model by determining an effective dose of C. jejuni that will colonize the poultry ceca at 35 days of age. A total of 90 birds were randomly divided into three experimental groups in six replications. The three experimental groups were 0, 1 X 104, and 1 X 108 CFU/bird C. jejuni. At 21 d of age, birds were orally inoculated with PBS (control) or 1 X 104 or 1 X 108 CFU/bird of C. jejuni. Feed intake and body weight were measured on days 0, 7, 14, 21, 28, and 35. On 3 and 7 dpi, gut permeability was measured by FITC-dextran assay. On 3, 7, and 14 dpi, C. jejuni loads in cecal content were quantified by plating and cecal tonsil CD4+:CD8+ cell ratio were quantified by flow cytometry. There were no significant differences (P > 0.05) in BWG and FCR between the treatment groups at any of the time points studied. Birds inoculated with 1 X 104 and 1 X 108 CFU of C. jejuni had 2.13 and 2.22 log10 at 3 dpi, 2.74 and 3.07 log10 at 7 dpi, and 3.89 and 4.21 log10 at 14 dpi increase in C. jejuni loads in the ceca compared to the control group, respectively. At 7 dpi, the CD4+:CD8+ cell ratio was (P < 0.05) higher in the 1 X 108 CFU of C. jejuni group than that in the 0 and 1 X 104 CFU/bird C. jejuni groups. There were no significant differences (P > 0.05) in serum FITC-d concentration between the treatment groups at any of the time points studied. This study found that 1 X 108 CFU/bird C. jejuni challenge produced greater cecal colonization and increased the CD4+:CD8+ cell ratio, compared to the Control and 1 X 104 CFU/bird C. jejuni groups, at 35 days old. It can be concluded that 1 X 108 CFU/bird C. jejuni inoculation at 21 d of age colonized the ceca at market age and induced host immune responses. |