Detection of Listeria monocytogenes through RealTime PCR and biosensor methods

Listeria monocytogenes is a foodborne pathogen causing listeriosis, especially in sensitive individuals such as children, pregnant women and persons with compromised immune systems. This pathogen has been isolated from different food products, but milk products surely play a major role in the epidemiology of this foodborne disease. Identification traditionally involved culture methods based on selective enrichment and plating followed by the characterization of Listeria spp. based on colony morphology, sugar fermentation and haemolytic properties. These methods are the gold standard, but in the last years more rapid tests were developed based on antibodies (ELISA) or molecular techniques (PCR or DNA hybridization). More recently, molecular methods were developed that target RNA rather than DNA , such as RT -PCR, real time PCR or nucleic acid sequence-based amplification (NA SBA). In this review, real-time PCR assays, protein chip methods and label-free SPR immunosensors were compared for their application in bacterial detection.