Skip to main content
ARS Home » Research » Publications at this Location » Publication #112886


item Gast, Richard
item Holt, Peter

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 4/17/2000
Publication Date: 8/15/2000
Citation: Gast, R.K., Holt, P.S. 2000. Deposition of salmonella enteritidis on and within egg yolks. Poultry Science Association Meeting Abstract.

Interpretive Summary:

Technical Abstract: Because egg yolk and albumen differ so greatly in their ability to support bacterial growth, the site of deposition of Salmonella enteritidis (SE) in eggs is pivotal for determining how quickly growth-inhibiting internal temperatures must be achieved in order to provide effective protection for consumers. When 100 cfu of SE was inoculated inside egg yolks, rapid and extensive growth was observed in all samples (to mean levels exceeding 10,000 cfu/ml after 6 hr and 100 million cfu/ml after 24 hr at 25 C). When a similar dose of SE was inoculated onto the exterior surface of intact egg yolk membranes, multiplication within the interior yolk contents occurred in only 10% of samples after 6 hr of incubation and in 75% of samples (reaching mean levels of about 10,000 cfu/ml) after 24 hr at 25 C. However, detectable multiplication of SE in yolk contents following inoculation onto the yolk membrane surface was observed in only 20% of samples incubated for r72 hr at 15 C. The second part of this study applied an oral infection model in laying hens to establish the proportion of contaminated eggs in which SE deposition was associated with the yolk membrane or was found inside the yolk contents.