Development of a PCR microplate-capture hybridizationmethod for simple, fast and sensitive detection ofSalmonella serovars in food

The authors have developed an easy and rapid detection and identification system for Salmonella spp. in food. The gene inv A was selected as the target sequence. Oligonucleotides derived from conserved regions of this gene were able to exclusively prime the amplification of a 389 bp fragment when Salmonella spp. DNA was used as the template. An internal Salmonella spp. specific DNA probe was used for confirmation of the amplified polymerase chain reaction (PCR) product, by Southern blot or microplate-capture hybridization assay. In this fashion the sensitivity of the method was increased 100-fold (4·5 fg total DNA). To validate the method, a total of 75 food samples was tested. The PCR-microplate capture hybridization assay is easy to perform and much faster than traditional detection methods for Salmonella spp. in food. Hybridization in microtitre plates is more readily observed than in Southern blot and is more sensitive than conventional agarose gel electrophoresis.