Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2019
Publication Date: 7/20/2020
Citation: Harris, C.E., Bartenfeld Jossel, L.N., Buhr, R.J. 2020. Recovery of Salmonella Enteritidis and Campylobacter Coli from inoculated and incubated hatching eggs. Poultry Science Association Meeting Abstract. 247, p.121.
Interpretive Summary: none
Technical Abstract: Vertical transmission of Salmonella from hen to offspring through the egg has been documented, but the data for Campylobacter is lacking. Salmonella and Campylobacter spp. are important human foodborne pathogens and increased knowledge on egg transmission would be beneficial for intervention strategies. The objective was to develop a S. enteritidis (SE) and C. coli (CC) inoculation protocol for hatching eggs and then recover the bacteria from embryos and egg contents during incubation. Three experiments determined inoculum levels for SE (exp 1), inoculum levels for CC (exp 2), and recovery at d 5 and 15 (exp 3). For all experiments, SPF white Leghorn eggs were collected 2-3 d prior to inoculation. For exp 1, there were 6 SE treatments (n=12): 1.22x10^3, 1.40x10^4, or 2.05x10^5 CFU yolk or albumen injected. For exp 2, there were 6 CC treatments (n=12): 1.50x10^1, 4.50x10^1, or 3.90x10^2 yolk or albumen injected. For exp 3, there were 4 treatments (n=22): SE 2.52x10^3 CFU yolk or albumen injected and CC 3.30x10^2 CFU yolk or albumen injected. For all inoculations, a hole along the equator of the egg was ground and inoculum was injected thru the shell membrane. Two eggs per treatment were sampled on d 0 to confirm inoculation. Eggs were incubated at 37.5°C and 54% relative humidity. On sampling days, embryos (when present) were aseptically removed from each egg and sampled separately from egg contents. Direct and enriched plating methods were performed on all sampling days to determine if egg contents or embryos were positive/negative. Kruskal-Wallis method was used to determine significance (p=0.05) and Dunn method was used for mean comparisons. For exp 1, there were no significant differences for SE recovery at d 2 for egg contents and d 5 for embryos. There were significant differences (p<0.0001) for egg contents recovery at d 5, with the yolk inoculations for all levels having 100%, while the albumen inoculations had a recovery of 0 – 20%. For exp 2, there was a significant difference in CC recovery from egg contents at d 2 (p=0.0360), with 100% recovery for albumen 3.90x10^2 CFU inoculation and 0 – 60% recovery for all other treatments. At d 5, there were no significant differences in CC recovery. For exp 3, recovery from egg contents at d 5 via yolk inoculation was 100% for SE and 90% for CC recovery. This was significantly higher (p=0.0050, 0.0087) compared to 40% for SE and 30% for CC for albumen inoculated. At d 15, there were no significant differences for SE, but CC egg contents were 100% positive for yolk inoculations compared to 50% for albumen (p=0.0137). These results show that there is potential for C. coli to persist in hatching eggs similar to S. enteritidis and be recovered from incubated eggs.