Methods for detection of viable foodborne pathogens: current state-of-art and future prospects

The ability to rapidly detect viable pathogens in food is important for public health and food safety reasons. Culture-based detection methods, the traditional means of demonstrating microbial viability, tend to be laborious, time consuming and slow to provide results. Several culture-independent methods to detect viable pathogens have been reported in recent years, including both nucleic acid-based (PCR combined with use of cell viability dyes or reverse-transcriptase PCR to detect messenger RNA) and phage-based (plaque assay or phage amplification and lysis plus PCR/qPCR, immunoassay or enzymatic assay to detect host DNA, progeny phages or intracellular components) methods. Some of these newer methods, particularly phage-based methods, show promise in terms of speed, sensitivity of detection and cost compared to culture for food testing. This review provides an overview of these new approaches and their food testing applications, and discusses their current limitations and future prospects in relation to detection of viable pathogens in food.