Submitted to: Applied Poultry Research
Publication Type: Review Article
Publication Acceptance Date: April 26, 1999
Publication Date: N/A
Interpretive Summary: Bacteria including the human pathogen salmonellae can readily penetrate the shell and membranes of an intact hatching egg. The results of this penetration is contamination of not only the embryo within but many other chicks during hatch in the commercial hatching cabinet. Such contamination can be carried onto the grow-out farm and pose a significant food safety hazard. Understanding the manner in which bacteria can penetrate the shell is important if one hopes to intervene. This paper is a review of the mechanisms involved in bacterial penetration, methods used to detect penetration and the stages of modern production which lend themselves to shell penetration and the subsequent potential contamination of many chicks. This information may be of use to hatchery managers, breeder manager and producers in their efforts to control the Salmonella problem in the commercial hatchery and it's product, the chick.
Technical Abstract: Bacteria including human enteropathogens can penetrate the outer structures of the egg. The mechanisms employed to gain entry of the egg are discussed. The most likely area on the egg and time during production and transport for bacterial penetration are reviewed. Methods used to test for or measure penetration of both the shell and associated membranes are discussed and compared. The natural defenses that an egg has against such attack are covered. The implications and consequences of bacterial penetration of the shell and membranes are described.