Submitted to: Poultry Science Association
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2012
Publication Date: July 1, 2012
Citation: Gast, R.K., Guraya, R., Guard, J.Y. 2012. Salmonella Enteritidis Deposition inside Eggs after Experimental Infection of Laying Hens with Different Oral Doses. Poultry Science Association. 91(Supplement 1):28. Technical Abstract: The continuing attribution of human Salmonella Enteritidis infections to internally contaminated eggs has necessitated the commitment of substantial public and private resources to risk reduction and testing programs for commercial laying flocks. Cost-effective risk reduction requires a detailed understanding of how S. Enteritidis infections in hens lead to pathogen deposition inside eggs. This study sought to resolve incompletely understood aspects of the relationship between S. Enteritidis oral exposure dose levels in experimentally infected laying hens and the frequency and location of subsequent egg contamination. In two trials, groups of specific-pathogen-free laying hens were experimentally infected with oral doses of 104, 106, or 108 cfu of phage type 4 S. Enteritidis. Eggs were collected 5-23 d PI and cultured for S. Enteritidis contamination in yolk and albumen. Increasing inoculation doses caused significantly (P < 0.05) more frequent egg contamination and a significant shift in the location of deposition toward albumen contamination. S. Enteritidis contamination was detected in 0.9% of yolks and 0.2% of albumens after inoculation of hens with 104 cfu, 4.0% of yolks and 1.7% of albumens following inoculation with 106 cfu, and 6.5% of yolks and 10.8% of albumens after inoculation with 108 cfu. These results demonstrate that oral exposure doses of S. Enteritidis for laying hens significantly affect important parameters of egg contamination which could potentially influence the effectiveness of risk reduction practices such as refrigeration.