Influence of the level and location of contamination on the multiplicationof Salmonella enteritidis at different storage temperatures in experimentally inoculated eggs

Prompt refrigeration to temperatures capable of restricting microbial growt h has been recommended as an approach to reducing the likelihood that conta minated eggs will transmit Salmonella enteritidis to humans. By using exper imentally contaminated egg components, the present study determined the ext ent to which small numbers of S. enteritidis could grow to more dangerous l evels at different temperatures over a period up to 3 d. This model was int ended to simulate the potential opportunities for S. enteritidis multiplica tion following oviposition and prior to the achievement of internal tempera tures able to prevent further microbial growth in eggs. At a relatively war mer incubation temperature (25 C) and with higher inoculum doses (150 cells ), rapid and substantial S. enteritidis multiplication often occurred, espe cially when the bacteria had an opportunity for access to yolk nutrients an d when contaminated eggs were incubated for 2 or 3 d before sampling. Exten sive multiplication of S. enteritidis was less frequently observed at lower inoculum doses (15 cells), shorter storage times (1 d), and lower temperat ures (10 to 17.5 C) and when contaminants were introduced into the albumen.