Bacteriological detection of Salmonella enteritidis in eggs: a review

The detection of Salmonella enterica serovar Enteritidis (SE) in eggs is hampered by a typically low prevalence of contaminated eggs, the low number of SE organisms in such eggs, and the presence of inhibitory substances in the egg albumin. For these reasons, the analysis of large pools of eggs is normally necessary, which presents logistic and microbiological challenges associated with a low number of target organisms from a large volume of sample matrix. In some studies using artificially inoculated eggs the standard procedure for Salmonella culture consisting of pre-enrichment, followed by selective enrichment and plating has been replaced by incubation of the egg pools at 25 degrees C to 37 degrees C followed by direct plating. However, in most cases using pools of naturally contaminated eggs, it may be necessary to enhance the traditional three-step method by addition of antibiotics or iron supplements.