USE OF FERROUS SULFATE AND IMMUNOMAGNETIC SEPARATION TO RECOVER SALMONELLA-ENTERITIDIS FROM RAW EGGS

Contaminated eggs or foods containing eggs have been a source of food borne salmonellosis, with a significant proportion of these outbreaks being attributed to Salmonella enteritidis. Since the level of contami nation in individual eggs or a pool of such eggs may be low, enrichmen t to increase cell numbers can take several days. Pre-enrichment of ra w blended eggs which have been supplemented with ferrous sulphate at a concentration of 35 mg/l, for 6 h at 37-degrees-C, significantly enha nced the growth of Salmonella. Using Dynabeads(R) Anti-Salmonella (Dyn al, Oslo), a new commercial product for selective enrichment of Salmon ella from food samples, we have defined a protocol based on immunomagn etic separation, specially for raw eggs. The application of this proto col enables definitive detection of Salmonella enteritidis from eggs w ithin 30 h.