New Rapid Detection Methods for Salmonella and Listeria

We are now very much aware of the hazards associated with salmonella and listeria in foodstuffs. Newer methodologies are compared with conventional techniques for their rapid detection. Recent developments in culture media are discussed, as is a new rapid culture test kit for salmonella. Novel techniques such as ELISA, nucleic acid probes and flow cytometry are described, and a comparative assessment is made of reported findings. Nucleic acid probe and ELISA assays are considerably quicker than traditional culture techniques but they would benefit from increased sensitivity; they show inferior specificity with listeria and are still dependent on an enrichment stage. Recent DNA amplification techniques could provide a solution to the problem of poor probe sensitivity and allow the direct detection of pathogens from food samples. Flow cytometry may have the potential for high sensitivity and specificity and could be useful for on‐line monitoring in factories.