SUMMARYOver 5700 hens eggs from 15 flocks naturally infected with Salmonella enteritidis were examined individually for the presence of the organism in either egg contents or on shells. Thirty-two eggs (0-6 %) were positive in the contents. In the majority, levels of contamination were low. Three eggs, however, were found to contain many thousands of cells. In eggs where it was possible to identify the site of contamination, the albumen was more frequently positive than the yolk. Storage at room temperature had no significant effect on the prevalence of salmonellapositive eggs but those held for more than 21 days were more likely (P < 0-01) to be heavily contaminated. In batches of eggs where both shells and contents were examined, I -% were positive on the former site and 0-9 % in the latter.

SUMMARYThe growth of Salmonella enteritidis PT4 in albumen around an intact yolk was governed by the age of the egg on inoculation. In the majority of eggs, held at 20°C, the bacterium was unable to grow rapidly until eggs had been stored for approximately 3 weeks. The multiplication of S. enteritidis in stored eggs appeared to be associated with alterations to the yolk membrane which allowed the bacterium to either invade the yolk or obtain nutrients from it. The rate at which egg contents change to permit the growth of S. enteritidis would appear to be temperature related and took place more rapidly when eggs were stored under conditions where temperatures fluctuated and, on occasions, reached 30 'C.

SUMMARYSalmonella enteritidis PT4 was recovered from fingers following the breaking of intact shell eggs artificially contaminated in the contents with the bacterium. Kitchen utensils used to mix egg dishes were salmonella-positive, sometimes after washing. Following the preparation of batter or the mixing of eggs, S. enteritidis was recovered from work surfaces over 40 cm from the mixing bowl. The bacterium survived well in thin, dry films of either batter or egg and, from an initial level of one cell per cm2, could be recovered from formica work surfaces 24 h after contamination.

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