Bacterial studies of egg shells in relation to the keeping quality of eggs.

The first consideration in the storage of eggs is the combatting of microbial spoilage. It is a well known fact that a high proportion of the eggs of the domestic hen (Gallus domesticus) are sterile internally in the bacterial sense at the time of laying, and for some time afterwards, though a microbial flora soon accumulates on the shell. However, there are instances in the literature of infection of the ovary by bacteria which can be transmitted to the egg. This is especially true with organisms of the Salmonella group responsible for bacillary white diarrhoea of the hen. This work was undertaken in order to obtain data which would provide a better understanding of the various factors which influence the microbial spoilage of eggs. The specific studies carried out have included (1) nutritional investigation to determine any possible relationship between the microbial penetration of the egg shell to the nutrition of the hen and to physical properties of the egg shell. (2) to test the feasibility of reducing bacterial penetration of the shell by impregnating the shell with (a) water repellants, (b) bactericidal agents and (c) by subjecting the egg to heat treatment