Detection of salmonellae in food

Salmonellae, particularly Salmonella enteritidis and Salmonella typhimurium , are a major cause of food poisoning with typical symptoms of diarrhoea an d fever. Consequently, food-standards legislation in many countries states that there should be less than one salmonella cell in 25 g of ready-to-eat food. In order to meet this criterion numerous methods have been developed. Initially any salmonella cells are resuscitated using a pre-enrichment med ium in order to recover cells that were injured during food processing. Enr ichment media are then used to encourage the growth of salmonellae and supp ress non-Salmonella bacteria prior to conventional plating onto selective a gar. This conventional approach is time-consuming and laborious. Consequent ly many alternative techniques involving PCR and enzyme-linked immunosorben t assays have been developed, and are reviewed here. (C) 2000 Lippincott Wi lliams & Wilkins.