A New Real-Time PCR Assay for the Specific Detection of Salmonella spp. Targeting the bipA Gene

A straightforward real-time polymerase chain reaction (PCR)-based assay was designed and evaluated for the detection of Salmonella spp. in food and water samples. This new assay is based on the specific detection of the bipA gene of Salmonella, which encodes a protein of the guanosine triphosphate (GTP)-binding elongation family that displays global modulating properties, by regulating a wide variety of downstream processes. The new method correctly identified all 48 Salmonella strains used in the inclusivity test, and did not detect all 30 non-Salmonella species tested. The method was evaluated by analyzing 120 diverse food and water samples enriched in buffered peptone water. The bipA-based real-time PCR assay showed 100% efficiency, sensitivity, and specificity compared to the invA-based method previously published, which was developed as a part of a European project for the standardization of PCR methods in food microbiology. The assay includes an independent internal amplification control (IAC) in each reaction to control false negative results.