Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/10/2023
Publication Date: N/A
Technical Abstract: Campylobacter spp. are important foodborne pathogens and in poultry flocks, horizontal transmission of Campylobacter has been confirmed while there is debate on whether vertical transmission through the egg can occur. Increased knowledge on the potential for egg transmission is beneficial when developing interventions, therefore the objective of this study was to evaluate the ability of Campylobacter to translocate from egg contents into the embryo during incubation. Three experiments were performed comparing recovery from eggs that were cold-stored (48 h) and incubated until D5 (Experiment 1; n=88), D15 (Experiment 2; n=191), or D18 (Experiment 3; n=212) of incubation. For all experiments, eggs were injected with 10^3 CFU Campylobacter coli into the albumen or yolk and sampling of the egg contents and viable embryos was performed during cold-storage (CS) and incubation. On D0, CSD1, CSD2, and D1, eggs contents were sampled, 1:1 diluted using buffered peptone water, and direct and enriched plated on Campy Cefex plates with 100ppm gentamycin in duplicate. On D5, D15, D18 of incubation, viable embryos were aseptically removed and sampled separately from egg contents; Campylobacter recovery from egg contents and embryos was performed with microbiological methods and 3M™ Molecular Detection System. Direct plate counts were recorded as Log10 CFU and analyzed using ANOVA; enriched results were analyzed with Kruskal-Wallis test to determine significance (p=0.05). Combined results from all experiments showed there was 100% recovery from both albumen and yolk injection sites on D0 and CSD1 with enrichment. For egg contents, Campylobacter recovery from yolk injected eggs was significantly higher than albumen injected eggs for CSD2 (63% vs. 100% enriched), D1 (0% vs. 77% enriched), D5 (34% vs. 94% enriched), and D15 (3% vs. 18% enriched). On D5, 4 live embryos from yolk injected were sampled, and all 4 were Campylobacter positive. On D15 of incubation, 18% of the yolk injected eggs had embryos that were Campylobacter positive, with 4 of the embryos that were Campylobacter positive with enrichment had egg contents that were negative. There was no recovery from egg contents or embryos of either injection sites on D18. There were no Campylobacter positive embryos recovered from the albumen injected eggs, but 9 out of 32 yolk injected eggs had positive embryos overall (D5+D15+D18). These results indicate that Campylobacter vertical transmission appears to be unlikely as Campylobacter may not be able to survive in the egg contents or embryos during the entire incubation period, but if it does occur, the location of the initial contamination is more likely the yolk contents.