Effect of fixed or changing temperatures during prolonged storage on the growth of Salmonella enterica serovar Enteritidis inoculated artificially into shell eggs.

The fate of Salmonella enterica serovar Enteritidis (SE) in whole, unbroken eggs was monitored during storage at fixed or changing temperatures after inoculation with 20-47 c.f.u. of SE. Eggs stored at 10 degrees C and 20 degrees C showed little or no bacterial growth over 6 weeks, while egg storage at 30 degrees C increased the percentage of the eggs that contained >10(6) c.f.u. after 3 weeks. Egg storage at 20 degrees C for 5 days followed by 10 degrees C caused only a few eggs with >10(6) c.f.u. after 2 weeks, whereas storage at 22-30 degrees C or 27-35 degrees C for 5 days followed by 25 degrees C induced a rapid increase of eggs that contained >10(6) c.f.u. after 1 or 2 weeks, respectively. Therefore, egg storage at 10 degrees C and 20 degrees C can control SE growth, although the temperature during egg storage and transportation from farm to table should also be taken into consideration.