Salmonella Enteritidis contamination of eggs from experimentally infected laying hens of four commercial genetic lines housed in conventional cages and enriched colonies.

Authors: Gast, Richard; REGMI, PRAFULLA - North Carolina State University; Guraya, Rupinder - Rupa; Jones, Deana; ANDERSON, KENNETH - North Carolina State University; KARCHER, DARRIN - Indiana University-Purdue University

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2019
Publication Date: 7/15/2019
Citation: Gast, R.K., Regmi, P., Guraya, R., Jones, D.R., Anderson, K., Karcher, D.M. 2019. Salmonella Enteritidis contamination of eggs from experimentally infected laying hens of four commercial genetic lines housed in conventional cages and enriched colonies. Poultry Science Association Meeting Abstract. 98(1):206.

Interpretive Summary:

Technical Abstract: Eggs contaminated with Salmonella enterica serovar Enteritidis continue to be internationally significant sources of human illness. The ability of this pathogen to colonize reproductive tissues in infected hens leads to deposition inside the edible contents of forming eggs. Although diverse environmental influences are known to affect the persistence and transmission of Salmonella infections in poultry, the food safety consequences of different management and housing systems are not fully understood. The present study evaluated the deposition of S. Enteritidis inside eggs laid by groups of experimentally infected laying hens representing four commercial genetic lines (white egg lines W1 and W2 and brown egg lines B1 and B2). Groups of hens from each line were housed at 648 cm2 of floor space per bird in both conventional cages and colony units enriched with access to perches and nesting areas. All hens were orally inoculated with 5.75 × 107 cfu of a mixture of two S. Enteritidis strains, and the internal contents of eggs laid 5-24 d post-inoculation were cultured to detect contamination. S. Enteritidis was found inside eggs laid between 7 and 21 d post-inoculation at an overall frequency of 2.47%, ranging from 0.25% to 4.38% for the four individual hen lines. The frequency of S. Enteritidis recovery from eggs was significantly higher (P < 0.05 in Fisher’s exact test) for line W1 than for line W2, and the egg contamination frequency for line B2 was significantly lower than from any other line. The overall incidence of S. Enteritidis isolation from white eggs (3.38%) was significantly greater than from brown eggs (1.56%). The frequencies of egg contamination with S. Enteritidis did not differ significantly between the two housing systems for any of the hen lines. These results suggest that S. Enteritidis deposition inside eggs can vary between genetic lines of infected laying hens, but housing these hens in two different systems did not affect the incidence of egg contamination.